Make siptwitter optional and rely on system qtweetlib on default

CMakeModules/FindQTweetLib.cmake

@@ -0,0 +1,31 @@
+# - Try to find QTweetLib
+#
+#  QTWEETLIB_FOUND - system has QTweetLib
+#  QTWEETLIB_INCLUDE_DIRS - the QTweetLib include directories
+#  QTWEETLIB_LIBRARIES - link these to use QTweetLib
+#
+# (c) Dominik Schmidt <dev@dominik-schmidt.de>
+#
+
+# Dependencies
+find_package(Qt4 REQUIRED)
+
+# Include dir
+find_path(QTWEETLIB_INCLUDE_DIR
+  NAMES QTweetLib/qtweetlib_global.h
+  PATHS ${KDE4_INCLUDE_DIR}
+)
+
+# Finally the library itself
+find_library(QTWEETLIB_LIBRARY
+  NAMES QTweetLib
+  PATHS ${KDE4_LIB_DIR}
+)
+
+SET( QTWEETLIB_LIBRARIES  ${QTWEETLIB_LIBRARY} ${QJSON_LIBRARIES} )
+
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(QTweetLib DEFAULT_MSG QTWEETLIB_LIBRARY QTWEETLIB_INCLUDE_DIR)
+
+MARK_AS_ADVANCED(QTWEETLIB_LIBRARIES QTWEETLIB_INCLUDE_DIR)
+