Fix app.config argument passing when using ct_run (take 2)

ct_run has changed its config key from -ct_config to -config,
thus, -config key, used to specify app.config now must be
placed after -erl_args
Merge pull request #411 from kittee/ct_appconfig_fix

Fix app.config argument passing when using ct_run (take 2)
Add {prefix, atom()} option for abnfc_opts

Specify the atom to use as a prefix for the decoder and generator
functions inside the parser's module.  Default is ''.
Add {parser, module()} option for abnfc_opts

Specify the module to use for parsing the ABNF grammars.  Default is
'abnfc_rfc4234'.
Add {qc, proplist()} option for abnfc_opts

Specify the options to use for the generator functions inside the
parser's module.  Default is [].