v0.4.22: Merge pull request #66 from mailgun/jeremy/charset

don't default to ascii charset for non-text Content-Types

v0.3.22

fix merge

v0.3.21: Mock network based tests so they are fast, deterministic, and can run

with no network access.

v0.4.20

Add option to headers.transform for decoding encoded-words

v0.3.20: Merge branch 'master' into stable

Conflicts:
	setup.py