Took the opportunity to undo the Godot changed made to the
opus source. The opus module should eventually be built in its
own environment to avoid polluting others with too many include
dirs and defines.
TODO: Fix the platform/ stuff for opus.
(cherry picked from commit d9a291f641)
speex module was only added while cherry-picking, as speex is removed
in the master branch but we don't want to break compatibility in 2.1.x.
Unbundling wasn't done as the module uses the internal speex_free,
so it would require some more work.
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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.