indicies over mask.true_indices in LK, doc fixes
doc changes in affine and homogeneous
remove debug break apart of invertible
Merge pull request #362 from jabooth/smallfixes

Assorted doc fixes
Fixes orthonormalize_against method edge case.
Merge branch 'master' into pca_hotfix
changes variable name and adds test of the edge case
Add test for Landmarks __str__
Merge pull request #365 from jalabort/pca_hotfix

Fixes orthonormalize_against method edge case.