using multiplicative LM augmentation

	modified:   cvt/vision/SparseBundleAdjustment.cpp
some improvements on checks and static jac eval

- jacobians at identity only evaluated once, statically
- removed unnecessary and wrong internal checks

	modified:   cvt/vision/KLTPatch.h
indent and corrected distance function

	modified:   cvt/vision/slam/Keyframe.cpp
maintaining pose relative to last active keyframe

- to better cope with map changes from SBA

	modified:   cvt/vision/slam/stereo/StereoSLAM.cpp
	modified:   cvt/vision/slam/stereo/StereoSLAM.h
ensuring SSD reduction and some more eleanup

	modified:   cvt/vision/KLTPatch.h
reducing patchsize

	modified:   cvt/vision/slam/stereo/DescriptorDatabase.h
KLT with check of alignment result

	modified:   cvt/vision/slam/stereo/StereoSLAM.cpp
	modified:   cvt/vision/slam/stereo/StereoSLAM.h
Add SIMD Normalized Cross Correlation
Simplify SIMD NCC using variance/covariance
Fix edge case of zero variance in SIMD NCC
Merge pull request #41 from mherb/ncc-simd

Add SIMD Normalized Cross Correlation