SFM: Rejection of unstable tracks, track color fix, misc
SFM: New sfmrecon app
SFM: Feature sets for detection and matching
UMVE: Fixed code due to API changes, simplified UI
SFM: Printing SSE enabled/disabled status
SFM: Descriptor discretization for matching
SFM: Added timings for feature detection
SFM: Option to disable undistortion
SFM: Updated sfmrecon with logging, documentation, and running full BA not after every view
SFM: Sanitized pairwise matching loop
SFM: Added matchability prediction
SFM: Scene normalization using mean, skip SfM option in bundler app
SFM: Bundler option to always run BA, SfM random seed
SFM: initial MVE style fixes to PBA
SFM: use C++ headers, remove `using' from PBA
SFM: remove some artifacts from PBA

(keep the interface intact for the moment, though)

* we don't want to build PBA as a standalone library
* we don't use the GPU part of PBA
UTIL: add AlignedAllocator
SFM: use AlignedAllocator for avec in PBA
SFM: specialize CameraT, Point2D, Point3D for float
SFM: specialize SparseBundleCPU, avec