[testing] Compare various descriptors

[griwodz]

Description

The test script runs VLFeat and PopSift on one or more images and creates the descriptors with orientations.
compareSiftFiles.cpp performs a brute force comparison of the output files and outputs sorted files and some distance computations.
These are then transformed bash and awk and rendered visually with gnuplot.

Features list

• New binary that compares two files containing SIFT descriptors. VLFeat and Matlab syntax supported.
• Scripts that compare VLFeat-compatible PopSift behaviour with original VLFeat behaviour. Requires new command line options of PR VLFeat compatibility #114 before they can work.

Implementation remarks

[griwodz]

@simogasp Is there any way of telling CodeFactor to check again after fixing the complaints? It keeps pointing me at a line where a very long function started when this PR was first created.

[simogasp]

@griwodz there is a re-run link in https://github.com/alicevision/popsift/pull/115/checks
Also if u login u can ignore the issue if it is not important or pertinent

[griwodz]

@simogasp Right now the checks have passed and I do probably not see any re-run links because of that. But I'm sure that I saw it before and pressing it didn't do the right thing. The error kept returning, still reporting a missing null-pointer check from a much earlier commit. Is it possible that there is a processing queue and the new commit were not really checked?

[fabiencastan]

Are we using OpenACC?

[griwodz]

We don't. It would simplify the grid filter, but the compiler is not part of the mainstream CUDA SDK yet. It should not be in the PR.