Changed freetype plugin to utilize CMake's FindFreetype.cmake rather than use a local one.

src/osgPlugins/freetype/CMakeLists.txt

@@ -22,6 +22,8 @@ SET(TARGET_H
 )
 
 SET(TARGET_ADDED_LIBRARIES osgText )
-SET(TARGET_LIBRARIES_VARS FREETYPE_LIBRARY )
+
+SET(TARGET_EXTERNAL_LIBRARIES ${FREETYPE_LIBRARIES} )
+
 #### end var setup  ###
 SETUP_PLUGIN(freetype)