Add {qc, proplist()} option for abnfc:file/2

Specify the options to use for the generator functions inside the
parser's module.  Default is [{max_recursion_depth,10}].

Implemented prototype to automatically limit the generator depth of
recursive ABNF grammars that would otherwise be untestable (by qc).

disable
   {max_recursion_depth,undefined}

automatic w/ specified depth
   {max_recursion_depth,non_neg_integer()}

manually specified terminals w/ specified depth
   {max_recursion_depth,{non_neg_integer(),Terminals::[atoms()]}}