Common/tests/DynamicMat_test.cpp
* Logging to a file the row extraction times while using DynamicMat
instead of cv::Mat.
* Increased number of files to load to test a more real case and see how
are the row extraction times.
.gitignore
* Ignored Test application folder.
Common/include/FileUtils.hpp
Common/src/FileUtils.cpp
* Declared and implemented saveDescriptors and loadDescriptors methods.

Common/src/DynamicMat.cpp
Common/tests/DynamicMat_test.cpp
* Refactored code to use loadDescriptors instead of loadFeatures, cleaned unnecessary variables after refactoring.

FeatureExtract/FeatureExtract.cpp
* Refactored code to use saveDescriptors instead of saveFeatures, cleaned unnecessary variables after refactoring.