Common/src/FileUtils.cpp
* In method FileUtils::loadDescriptors, clearing matrix before loading
its content.

VocabLib/include/InvertedIndex.h
VocabLib/src/InvertedIndex.cpp
VocabLib/tests/InvertedIndex_test.cpp
* Added incomplete yet not functional implementation of the inverted
index.

VocabLib/include/VocabTree.h
* Made available in the base no/templated class the methods for
saving/loading the inverted index.
* Moved wordId from the save/load methods of the vtree to those of the
inverted index.
* Added preprocessor directives to some output status messages.
* Moved validation of inverted index specific attributes to the
appropriate class.

VocabLib/tests/VocabTree_test.cpp
* Refactored tests to test indenpdences of tree and inverted index.
* Testing whether DB BoW Vectors are normalized.

VocabLib/tests/Makefile
* Disabled preprocessor directives.