[ticket/9975] Moved a few E_USER_ERROR errors to /language

There were a few error messages that a user could experience that would, previously, be without any the ability to be localized. There are some more E_USER_ERRORs that I did not change to a constant, for example the error message that is displayed if there aren't any folders in /language.

PHPBB3-9975

phpBB/language/en/captcha_recaptcha.php

@@ -46,4 +46,5 @@ $lang = array_merge($lang, array(
 	'RECAPTCHA_PRIVATE_EXPLAIN'		=> 'Your private reCaptcha key. Keys can be obtained on <a href="http://www.google.com/recaptcha">www.google.com/recaptcha</a>.',
 
 	'RECAPTCHA_EXPLAIN'				=> 'In an effort to prevent automatic submissions, we require that you enter both of the words displayed into the text field underneath.',
+	'RECAPTCHA_SOCKET_ERROR'		=> 'There was a problem connecting to the RECAPTCHA service: could not open socket. Try again later.',
 ));

phpBB/language/en/common.php

@@ -313,6 +313,7 @@ $lang = array_merge($lang, array(
 	'IN'						=> 'in',
 	'INDEX'						=> 'Index page',
 	'INFORMATION'				=> 'Information',
+	'INSECURE_REDIRECT'			=> 'Tried to redirect to potentially insecure url.',
 	'INTERESTS'					=> 'Interests',
 	'INVALID_DIGEST_CHALLENGE'	=> 'Invalid digest challenge.',
 	'INVALID_EMAIL_LOG'			=> '<strong>%s</strong> possibly an invalid email address?',
@@ -638,6 +639,7 @@ $lang = array_merge($lang, array(
 	'STATISTICS'				=> 'Statistics',
 	'START_WATCHING_FORUM'		=> 'Subscribe forum',
 	'START_WATCHING_TOPIC'		=> 'Subscribe topic',
+	'STYLE_NOT_FOUND'			=> 'Could not get style data',
 	'STOP_WATCHING_FORUM'		=> 'Unsubscribe forum',
 	'STOP_WATCHING_TOPIC'		=> 'Unsubscribe topic',
 	'SUBFORUM'					=> 'Subforum',

phpBB/language/en/mcp.php

@@ -250,6 +250,8 @@ $lang = array_merge($lang, array(
 	'ONLY_TOPIC'			=> 'Only topic “%s”',
 	'OTHER_USERS'			=> 'Other users posting from this IP',
 
+	'QUICKMOD_ACTION_NOT_ALLOWED' => "%s not allowed as quickmod",
+
 	'PM_REPORT_CLOSED_SUCCESS'	=> 'The selected PM report has been closed successfully.',
 	'PM_REPORT_DELETED_SUCCESS'	=> 'The selected PM report has been deleted successfully.',
 	'PM_REPORTED_SUCCESS'		=> 'This private message has been successfully reported.',