Upgrade Matplotlib's libfreetype dependency

This is prompted by a recent upstream change that updated Matplotlib.

https://groups.google.com/forum/#!topic/openedx-ops/qpsHXs4okHs
Merge pull request #9

from Stanford-Online:stv/rc
into Stanford-Online:rc
Allow session cookie name to be customized

This was manually cherry-picked out out edx:master.
Merge pull request #10

from Stanford-Online:stv/cookie
into Stanford-Online:rc
replace geturl with a shell out to curl - to fix broken certificate management
Mark CME as 'production'

This was needed to disable HTTP AUTH.
Merge pull request #11

from Stanford-Online:github/keys
into Stanford-Online:rc
Merge remote-tracking branch 'origin/rc' into release