Sync with Alchemy, includes much awaited lib updates for Linux

Applies ALCH-420 - Replace all invisiprims with fully transparent texture and remove dead code paths
-ARC no longer takes invisis into consideration.

Syncs some script keywords updates.

Changes all "\n" in llfloaterabout.cpp to '\n' because screw.dat

indra/cmake/Copy3rdPartyLibs.cmake

@@ -137,7 +137,7 @@ elseif(LINUX)
         libatk-1.0.so
         libexpat.so
         libexpat.so.1
-        libfreetype.so.6.12.0
+        libfreetype.so.6.12.3
         libfreetype.so.6
         libfreetype.so
         libGLOD.so