update change log for version 1.4.6

renamed variables for clarity, changed pow(2.0,... to ldexp(1.0,... f…

…or style and negligible gains in efficiency

Merge branch 'dso' of https://github.com/bbrister/SIFT3D into dso, fo…

…r 1.4.4 release

update change log for version 1.4.2

update change log for version 1.4.2

update change log, build for version 1.4.1

updated change log