VocabMatch/VocabMatch.cpp
* Added filepath to the file containing the list of db keypoints
filenames as new parameter to the program.
* Cleaning standard output useless messages.
* Loading file of db images ground truth into a map to tackle down the
problem of associating db images scores with its ground truth info when
some images might be distractors and hence don't have any landmark id
associated.
* Validating landmark id.
* Computing number of landmark ids in loop for loading db ground truth
files.
* Implemented logic for filling correctly map with the ground truth
information.
* Implemented logic for loading file with the list of db keypoint
filenames, further used for associating db image id with its filename.
* Refactor due to variable names changes.
* Retrieving landmarks of each one of the top scores by using the
introduced map structure and the list of db keypoint filenames.