[raster] ST_SetRotation does not preserve the angle between basis vectors

[dzwarg]

SetRotation does not preserve the angle between the basis vectors. (The angle between i_b and j_b is different after St_SetRotation is called. Both axes should be rotated the same.)

I remedied this in my working git repo with an implementation of DevWikiRealParameters and DevWikiAffineParameters, upon which st_rotation and st_setrotation now depend (in that repo). We can either pluck out the bits and pieces relevant to this issue or wait for the gen2 iterator...or you can reimplement the algorithms from scratch. Plucking out bits and pieces may be a bit sticky, since the new code is tested with CUnit tests, and the postgis repo lacks this infrastructure.

The commit which fixes this in bnordgren's repo is:  https://github.com/bnordgren/postgis/commit/06f9e65537e385f2adcb1b9ae166f50f5c7ad986

To browse source:  https://github.com/bnordgren/postgis/tree/ri-gen2-svn