A Dockerfile for easy Mailpile testing/development
Merge branch 'docker' of github.com:kermit666/Mailpile into pull-zone

Moved docker chapter to the dev section of the README instead of being
at the top.

Conflicts:
	.gitignore
Added 'make virtualenv' target -- includes adding mailpile.plugins to setup.py
Merge branch 'virtualenv' of https://github.com/ulikoehler/Mailpile into pull-zone

Conflicts:
	.gitignore
Remove mp-virtualenv on make clean
Document make virtualenv