upgrade Pillow to 2.3.0

1.7.8 doesn't compile on Ubuntu 14.04
requirements/libs.txt should be requirements.txt

also fixes a markdown formatting problem
Merge pull request #37 from nikolas/readme-fix

Readme fix: requirements/libs.txt should be requirements.txt
Merge branch 'pillow-2.3.0' of https://github.com/thraxil/mediathread

Conflicts:
	requirements.txt
Merge branch 'master' of github.com:ccnmtl/mediathread