Merge pull request mailgun#128 from mailgun/ajay/qp_encoding_cleanup

Ajay/qp encoding cleanup

For text part, prefer quoted printable over base64

Quoted Printable is good enough, we don't need base64.
For mostly ascii data, base64 adds quiet a bit of bandwidth overhead.
Also, use quopri directly, email.encoders forces encoding of space
character.
Implement metrics for flanker parts

Merge pull request mailgun#118 from mailgun/maxim/develop

Make DecodingError message safe

Decode to UTF-8 before logging

This fixes an exception where a header contains a character that cannot
be converted to ASCII, e.g. 0xea.  Python will attempt to encode unicode
strings to ascii before passing them to b64encode (which passes it to the
internal C function binascii.b2a_b64).  This commit forces encoding of
the string as UTF-8, which contains no characters that cannot be encoded.

Trim exception when getting string representation of Error.

Merge pull request mailgun#107 from mailgun/sergey/inline

fix file name for inline attachments

Merge branch 'master' into stable

Conflicts:
	setup.py

Version bump for release.

Merging in master.

Bumped version of dnsq.