remove libircclient from shared library

* removes libircclient from libzetaglest shared library because the
editor and g3d_viewer also link against libzetaglest. Those 2 binaries
don't need libircclient support

* libircclient is now built directly into only the zetaglest binary

* moved libircclient from source/shared_lib because it's no longer part
of the shared library

* libircclient put in dir "external/" because it is an "external" or
"3rd" party library. The @Supertux project does something similar

external/libircclient/doc/sources/API_reference_constants.rst

@@ -0,0 +1,126 @@
+
+Constants
+~~~~~~~~~
+
+This section describes contstants such as options and the error codes.
+
+Errors
+^^^^^^
+
+.. c:macro:: LIBIRC_ERR_OK
+
+(0): No error
+
+
+.. c:macro:: LIBIRC_ERR_INVAL
+
+(1): An invalid value was given for one of the arguments to a function. For example, supplying the NULL value as a channel argument of :c:func:`irc_cmd_join` produces this error.
+
+
+.. c:macro:: LIBIRC_ERR_RESOLV
+
+(2): The host name supplied for :c:func:`irc_connect` function could not be resolved into valid IP address.
+ 
+
+.. c:macro:: LIBIRC_ERR_SOCKET
+
+(3): The new socket could not be created or made non-blocking. Usually means that the server is out of resources, or (hopefully not) a bug in libircclient. See also :ref:`faq_err_socket`
+
+.. c:macro:: LIBIRC_ERR_CONNECT
+
+(4): The socket could not connect to the IRC server, or to the destination DCC part. Usually means that either the IRC server is down or its address is invalid. 
+For DCC the reason usually is the firewall on your or destination computer, which refuses DCC transfer.
+
+.. c:macro:: LIBIRC_ERR_CLOSED
+
+(5): The IRC connection was closed by the IRC server (which could mean that an IRC operator just have banned you from the server - test your client before connecting to a public server), or the DCC connection
+was closed by remote peer - for example, the other side just terminates the IRC application.  Usually it is not an error.
+
+
+.. c:macro:: LIBIRC_ERR_NOMEM
+
+(6): There are two possible reasons for this error. First is that memory could not be allocated for libircclient internal use, and this error is usually fatal.
+Second reason is that the command buffer (which queues the commands ready to be sent to the IRC server) is full, and could not accept more commands yet. 
+In the last case you should just wait, and repeat the command later.
+
+
+.. c:macro:: LIBIRC_ERR_ACCEPT
+
+(7): A DCC chat/send connection from the remote peer could not be accepted. Either the connection was just terminated before it is accepted, or there is a bug in libircclient.
+ 
+
+.. c:macro:: LIBIRC_ERR_NODCCSEND
+
+(9):  A filename supplied to :c:func:`irc_dcc_sendfile` could not be sent. Either is is not a regular file (a directory or a socket, for example), or it could not be read. See also :c:macro:`LIBIRC_ERR_OPENFILE`
+
+
+.. c:macro:: LIBIRC_ERR_READ
+
+(10): Either a DCC file could not be read (for example, was truncated during sending), or a DCC socket returns a read error, which usually means that the network connection is terminated.
+
+.. c:macro:: LIBIRC_ERR_WRITE
+
+(11):  Either a DCC file could not be written (for example, there is no free space on disk), or a DCC socket returns a write error, which usually means that the network connection is terminated.
+
+.. c:macro:: LIBIRC_ERR_STATE
+
+(12):  The function is called when it is not allowed to be called. For example, :c:func:`irc_cmd_join` was called before the connection to IRC server succeed, and :c:member:`event_connect` is called.
+
+.. c:macro:: LIBIRC_ERR_TIMEOUT
+
+(13):  The DCC request is timed out. There is a timer for each DCC request, which tracks connecting, accepting  and non-accepted/declined DCC requests. For every request this timer 
+is currently set to 60 seconds. If the DCC request was not connected, accepted or declined during this time, it will be terminated with this error.
+
+.. c:macro:: LIBIRC_ERR_OPENFILE
+
+(14): The file specified in :c:func:`irc_dcc_sendfile` could not be opened.
+
+.. c:macro:: LIBIRC_ERR_TERMINATED
+
+(15): The connection to the IRC server was terminated.
+
+.. c:macro:: LIBIRC_ERR_NOIPV6
+
+(16): The function which requires IPv6 support was called, but the IPv6 support was not compiled into the application
+
+.. c:macro:: LIBIRC_ERR_SSL_NOT_SUPPORTED
+
+(17): The SSL connection was required but the library was not compiled with SSL support
+
+.. c:macro:: LIBIRC_ERR_SSL_INIT_FAILED
+
+(18): The SSL library could not be initialized.
+
+.. c:macro:: LIBIRC_ERR_CONNECT_SSL_FAILED
+
+(19): SSL handshare failed when attempting to connect to the server. Typically this means you're trying to use SSL but attempting to connect to a non-SSL port.
+
+.. c:macro:: LIBIRC_ERR_SSL_CERT_VERIFY_FAILED
+
+(20): The server is using an invalid or the self-signed certificate. Use :c:macro:`LIBIRC_OPTION_SSL_NO_VERIFY` option to connect to it.
+
+
+.. _api_options:
+
+Options
+^^^^^^^
+
+.. c:macro:: LIBIRC_OPTION_DEBUG
+
+If set, enables additional debug output which goes to STDOUT.
+
+.. c:macro:: LIBIRC_OPTION_STRIPNICKS
+
+If set, strips the event origins automatically. Every event has an origin (i.e. who originated the event). The origin usually looks like *nick!host@ircserver*, 
+i.e. like *tim!home@irc.server.net*. Such origins can not be used in IRC commands, and need to be stripped (i.e. host and server part should be cut off) before using. 
+This can be done either manually by calling :c:func:`irc_target_get_nick`, or automatically for all the events if this option is set.
+
+
+.. c:macro:: LIBIRC_OPTION_SSL_NO_VERIFY
+
+By default the SSL connection is authenticated by verifying that the certificate presented by the server is signed by a known trusted certificate authority. 
+Since those typically cost money, some IRC servers use the self-signed certificates. They provide the benefits of the SSL connection but since they are 
+not signed by the Certificate Authority, their authencity cannot be verified. This option, if set, disables the certificate verification - the library 
+will accept any certificate presented by the server.
+
+This option must be set before the :c:macro:`irc_connect` function is called.