Symbolic string encode/decode

[pschanely]

We'd like preserve symbolics across encode/decode for all encodings. But we only can do this for some right now.

The current checklist follows. Suggest codecs to tackle next.

• [x] ascii
• [x] utf-8
• [x] latin-1

Or, in case you want to help, CrossHair codecs are implemented here, and these are some of my original research notes:

Python supports a lot of encodings, in total. I did a little digging around in PyPy, and there are some pure python implementations that we could possibly lean on somehow. A lot of the logic is here.

[pschanely]

Ascii, utf8, and latin-1 all have symbolic support for encode/decode in v.0.0.20!

Reply below to vote for other encodings that would be helpful for you.