SFM: Added check that prebundle is writable
Apps: Added OpenMVG support to makescene
SFM: Removed unused include, matrix initialization in test
MATH: Changed SVD behavior for matrices with cols > rows
SFM: Final SVD preparations for removing Eigen
Tests: Changed SVD and related tests, SVD not fully working yet
Merge branch 'master' into sfm

Conflicts:
	apps/makescene/makescene.cc
Tests: More SVD test cases
MATH: Fixed SVD and test cases
SFM: Switched to own SVD code (deprecates use of Eigen)
Merge branch 'sfm' of github.com:simonfuhrmann/mve into sfm
SFM: Fixed BundlerIncremental::is_initialized query
UMVE: Added SfM UI features