Add modules whitelist

[c0d3z3r0]

No description provided.

[corna]

Thanks for this PR. Just a couple of things:

• this breaks backwards compatibility, as now -k can't be used alone anymore. You can add nargs="?", default="" to parser.add_argument to have
  • a string if the list of the modules has been passed
  • an empty string (the default) if nothing has been passed
  • None if -k has been specified, but no list has been provided
    Now you can just replace if keep_modules == "all": with if keep_modules == None:.
• I think it's better if we pass a list of strings (or None for "all modules") to the two check_and_remove_modules functions, instead of a comma-separated string. Move and adapt this part before calling check_and_remove_modules
• break the lines if they are more than 80 characters

[c0d3z3r0]

"None if -k has been specified, but no list has been provided"
-> Nope ;-) This is the one thing I needed sooo many times... but that does not work since argparse cannot know if the last argument after -k is -k's or file's value.

I found a way to solve this but that is very ugly.
-k, nargs="?", default="" works for these invocations:
./me_cleaner.py -k touch_fw image.bin
./me_cleaner.py -k -- image.bin
./me_cleaner.py image.bin -k
but not for ./me_cleaner.py -k image.bin for the reason stated above.

I think this is very, very ugly so my idea would be keeping -k as backward compatibly parameter and add two new parameters -W,--module-whitelist and -B, --module-blacklist or maybe -R (remove) and -K (keep). This way one can specify -k to keep all modules or one of -W, -B (-R, -K).
@corna What do you like better?

[c0d3z3r0]

@corna any progress here? is there anything I can do?