Command parser mangles unicode inputs

[kevsmith]

The new command parser added to Piper for the 0.16 Cog release mangles Unicode inputs. The mangling has two sources:

• Use of Erlang binary and iolist conversion functions (:erlang.binary_to_list/1 and :erlang.iolist_to_binary/1) in the leex generated lexers and yecc generated parsers.
• Omission of the unicode option in calls to re:run/3 and re:replace/3 also in the generated lexers and parsers.

This bug is likely present in the old parser as well.

[kevsmith]

The fix pending in operable/piper#35 ensures Unicode passes thru the parsing pipeline unmangled. It does not add support for Unicode bundle or command names as doing so would require deeper changes to the parsers and test suite.

That said, making the parsing pipeline Unicode-safe is a necessary first step towards supporting Unicode bundle and command names.

[kevsmith]

Duplicates #1125