This is probably due to an error on the gamasutra web page demonstrating this.
It caused left-handed rotations rather than right handed rotations. Should be
fixed now.
Also move osg across to using radians for angular paramters by default.
By defining USE_DEGREES_INTERNALLY you can get the OSG to revert to
the old style degrees. This later feature is deprecated and only meant
for helping comptability in the interim.
Also added Matrix::ensureRealized() to support the lazy initialization of Matrix, whilest keeping the implementation robust so that external calls to Matrix which get values do so on an initialized matrix.
