Common/include/FileUtils.hpp
* Declared functions for saving/loading keypoints.

Common/src/FileUtils.cpp
* Defined functions for saving/loading keypoints.
* Fixed exception messages.

FeatureExtract/FeatureExtract.cpp
* Saving keypoints to a file in disk.

VocabLib/include/DirectIndex.hpp
* Added default parameter to the class constructor.
* Declared methods for saving, loading, and clearing index.

VocabLib/include/VocabTree.h
* Fixed exception messages.
* Implemented methods for saving/loading direct index.

VocabLib/src/DirectIndex.cpp
* Defined methods for saving and loading index.
* Leaved commented clearing method implementation.