Fixes GCC 5 warnings of the form:
core/io/http_client.cpp:288:9: warning: enumeration value 'STATUS_SSL_HANDSHAKE_ERROR' not handled in switch [-Wswitch]
core/io/marshalls.cpp:806:9: warning: enumeration value 'AABB' not handled in switch [-Wswitch]
Those can be trivial cases where adding a default fallback is the solution,
or more complex issues/hidden bugs where missed values are actually meant
to be handled.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
This is a bullet wrapper that allows Godot to use Bullet physics and benefit about all features.
Also it support all specific Godot physics functionality like multi shape body, areas, RayShape, etc..
It improve the Joints, Trimesh shape, and add support to soft body even if Godot is not yet ready to it.
