commands: optimize binary search

commands: optimize binary search

Since there is a lot of options and lot of searches,
use binary search to keep strcmp at minimum.

The interesting part is - alphabetically sorted array contains
duplicates and some of them are not the 'right anwer', so
after we find matching string but not matching long_ARG,
we may need to check if the surrouding strings are the right matching
one.

The single loops is used also for strictly define --foo_long
(i.e. --stripes)  and just differs at final part.

TODO1: replace strstr call with some flag (just like short_opt).
TODO2: drop '--' from being stored and tests by strcmp.