Merge pull request #628 from est77/master

Fixed error in last commit
Merge pull request #629 from est77/master

Fixed PR comments. Changed some instances of for (int to for (size_t.
partially reverted 824d30f4083731739ce94dde9103e1a1141a267d: Imath::Matrix::operator[] takes an int, not a size_t.
use size_t instead of int to index coefficients of a foundation::UnalignedMatrix44.
tweaked formatting.
fixed another type mismatch.
cosmetics.
fixed foundation::Quaternion::rotation() factory method, and added foundation::rotate() free function.
added a unit test.
Fixed bug in python ProjectFileWriter binding.