parser: allow specifying the parser config file
The parser config file can affect the parsers behavior during tests. Allow overriding the default location with the option
--config-file=
the option must be the first option in the commands argument list.
Also provile a --print-config-file
option to display what the parser is using for a config file.
BugLink: http://bugs.launchpad.net/bugs/1277711 Signed-off-by: John Johansen john.johansen@canonical.com