BUG/MEDIUM: pattern: Segfault in binary parser

The functions pat_parse_* must return 0 if fail and the number of
elements eated from **text if not fail. The function pat_parse_bin()
returns 0 or the length parsed. This causes a segfault. I just apply the
double operator "!" on the result of the function pat_parse_bin() and
the return value value match the expected value.
MINOR: pattern: move functions for grouping pat_match_* and pat_parse_* and add documentation.
MINOR: standard: The parse_binary() returns the length consumed and his documentation is updated

Actually the values returned by this function is never used. All the
callers just check if the resultat is non-zero. Before this patch, the
function returns the length of the produced content. This value is not
useful because is returned twice: the first time in the return value and
the second time in the <binstrlen> argument. Now the function returns
the number of bytes consumed from <source>.