Message 109051 - Python tracker

Secondly, this is my attempt to add the more sensibly named {to|from}bytes methods, and to deprecate {to|from}string. 

I doubt it's perfect, maybe there's some policy on deprecating methods that I didn't find? This may be better discussed in a separate forum, eg a separate issue or python-dev maybe? I wouldn't know.

The unpatched test suite passes with the rest of this patch applied. (unless using -Werror)