Data compressor based on rANS algorithm

possible arguments:

-v --version
    Prints current program version
-h --help
    Prints arguments informations
-e --encode file_path
    Encodes file indicated by "file_path"
-d --decode file_path
    Decodes file indicated by "file_path"

Original work about asymmetric numeral systems (ANS) https://arxiv.org/pdf/1311.2540.pdf