This module realize work with revisions file.
Revisions looks like dictionary with key funcName and value is the tuple: hash + source:
{"funcName1": (funcName1_hash, funcName1_source), "funcName2": (funcName2_hash, funcName2_source), ...}
File for revision contains list:
[revision's last date-n-time, {revisions}]
Empty revision-file looks like this: [None, {}]