Common/FunctionUtils.cpp
Common/FunctionUtils.hpp
* Comments cleaning.

VocabLib/include/VocabTree.h
* Added new method for retrieving a database BowVector given its image
index.
* In method build, added data set emptiness validation.
* In method save_tree fixed bug due to wrong data types. A tree nodes
centers might be pointers to other than uchar, and the data set might
not be initialized hence the correct type for constructing centers Mat
is that given by the template type.
* In methods transform, quantize, addImageToDatabase, and scoreQuery,
added commented pieces of code for monitoring internal variables value
in case needed for bug fixing. They are typically buggy methods.

VocabMatch/VocabMatch.cpp
* Moved to the top declaration and assignment of variable holding the
number of candidates since it is needed by the writeHeader method from
HtmlResultsWriter.
* Added commented piece of code to monitor the resulting db BoW vector,
its typically a good point for fixing bugs.