tree fb423b7bdd635d42b17bd1e2e952583a15db9579
parent afe93546b67cee0ad205fe8044325646ed5deea9
author Chris Sweeney <sweeney.chris.m@gmail.com> 1502229344 -0700
committer Chris Sweeney <sweeney.chris.m@gmail.com> 1502229344 -0700

Add new Schur specialization for 2, 4, 6.

The row, E, F block pattern 2, 4, 6 is a common one for
bundle adjustment with reprojection error (2 residuals),
homogeneous 3d points (4 params in the E-block), and camera
poses (3 rotation + 3 position = 6 params for the
F-block). This provides a major speedup for BA in the
TheiaSfM library and likely in other applications.

Change-Id: If5df8bfadc7f154856b74c3b38479c14856db47d