Removed the is_local_tree property from compo/shader/texture node trees. This was using an ID property, which causes trouble with 2.62 builds (possibly later) due to an old bug that causes ID properties in local node trees not loaded correctly. The bug has been fixed since then, but creating id properties will break with these builds. The property was not really necessary, so removing it will make it work as long as users don't add id properties themselves.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55422 954f8c5b-7b00-dc11-b283-0030488c597c