2.86
fix whitespace formatting in cmake files
fix in structure alignment of btMultiBodyLinkDoubleData and btMultiBodyDoubleData causing serialization issue in URDF/SDF loading in double-precision mode on Windows 32bit. (it was fine on Mac/Linux 64bit) bump serialization version to 2.85, as we change the file format fix in name clash in makesdna.cpp -> intptr_t is already defined.
add the 'extras' and Bullet 2 tests, to make it easier to create a new intermediate release