gpg: Allow debug flag names for --debug.
* g10/gpg.c (opts): Change arg for oDebug to a string. (debug_flags): New; factored out from set_debug. (set_debug): Remove "--debug-level help". Use parse_debug_flag to print the used flags. (main): Use parse_debug_flag for oDebug.
- Signed-off-by: Werner Koch <wk@gnupg.org>