FeatureExtract/FeatureExtract.cpp
* Parameterized in the program the detector and descriptor type.
* Implemented validation for the just added program parameters.
* Refactored program accordingly to use the new parameters.

VocabLib/src/VocabTree.cpp
* Comment cleaning.
* Warning removal.
* Unused variables removal.

VocabLearn/VocabLearn.cpp
* Comment cleaning.