Blender Git Loki

Bundle adjustment improvements

- Get rid of rotation matrix parameterization,
use angle-axis instead.

Also Joined rotation and translation into a
single parameter block.

This made minimization go significantly faster,
like 1.3x times in average.

- Fix first camera when bundling. This is to
address orientation ambiguity.

Reconstruction result could still vary in
size, but that's another issue to be addressed
later.

Additional change:

Split EuclideanBundleCommonIntrinsics into
smaller functions, so it's now a bit easier
to follow.