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

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

Prototype that automatically limits the generator depth of recursive
ABNF grammars that would otherwise be untestable (by qc).

disable
   {sized_recursion_limit,undefined}

automatic w/ specified limit
   {sized_recursion_limit,non_neg_integer()}

specified terminals w/ specified limit
   {sized_recursion_limit,{non_neg_integer(),Terminals::[atoms()]}}