Added an additional vector<short> which keeps track of mappings from
centroid clusters to VFH signatures -- which occurs when axes can't be
disambiguated.

Also, ensured that the width and height are set properly on output when compute,
computeFeature, and computeRFAndShapeDistribution are called.
Merge pull request #738 from mohawkjohn/master

Improvements to OUR-CVFH Estimation, including mapping from clusters to features and doc fixes