Changes

Major overhaul of run_bindiff_all.py

CLUBB ticket #1102 - pull request #1113
- Changed the outputs to be more evocative and differentiating between types of differences: Now we can distinguish between differences in the set of variables or differences in specific variables
- Fixed the issue where a variable that appears in only one of the compared files would either not be detected or cause the script to crash, depending on the order of input.
- Changed file output structure
- Changed case handling depending on existing files:
    - Case is still treated even if it is commented in RUN_CASES
    - Case is still treated even if not all files exist and messages are printed accordingly