Test if clang is defined in CC/CXX/LD - this allows a specific version of clang to be defined
move appending -DTYPED_METHOD_BIND to keep clang options together
move sanitize option out of use_llvm test, gcc48+ also supports sanitize=address
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-Moved drawing code to a single function that takes linked list (should make it easier to optimize in the future).
-Implemented Z ordering of 2D nodes. Node2D and those that inherit have a visibility/Z property that affects drawing order (besides the tree order)
-Removed OpenGL ES 1.x support. Good riddance!
-Fixed many bugs in stretch mode
-Fixes to camera project and unproject as consequence of the above
-added setget to script (documented in script doc)
-more fixes to collada exporter for blender
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Build System:
-Big clean up of SCons, changed how builds are done to a much cleaner method (check the Github Wiki for instructions).
-Deactivated BlackBerry10 (sorry), if no mantainer found (or BlackBerry does not send us a Passort ;), platform will be removed as we have no longer devices to test.
Engine:
-Removed deprecated object and scene format (was in there just for compatibility, not in use since a long time).
-Added ability to open scenes even if a node type was removed (will try to guess the closest type).
-Removed deprecated node types.
