Add a DEFLATE string

[Adriandmen]

:)

[eaglgenes101]

DEFLATE is a good workhorse, but it's been a few decades, and it isn't best in class anymore. I would suggest these string forms for this language:

A short string, which uses a prebaked entropy encoding to encode common short strings very well (something like shoco),

and a long string, using a modern-strength compression algorithm complete with adaptive encoding and giant lz windows, to encode strings with redundancy.

[fionafibration]

Here's a good implementation of Smaz in pure python: https://github.com/CordySmith/PySmaz/