Changed the key names for most localized strings to follow "The Rules"

See https://groups.google.com/forum/#!topic/cozy-cloud/Y6LeAATyZog for the discussion.

These changes were made using a sed script. I then ran "coffee lint" (which passed all tests except two for line lengths that were pre-existing problems) and "coffee test" (which passed until hitting an issue with connect 3.0, which I believe is also pre-existing). I then did a "coffee convert" and tested using "node server". From my limited browsing around things seem to work. However, given the fact the changes were automated and this is my first attempt at a "large" update, it would be good if someone gave this a good going over, since it is proving out the approach I will take on the other repos if this passes muster.

Since the sed script is a one-time thing I am choosing not to include it in the commit, but will probably post it to the Google Group for documentation/discussion of my approach.

Note there may be a few keys that got missed due to the automated approach. My plan is to be looking closely at the key names in the en.coffee file as I now switch to working on the English translation phrases in the values, and if I see any that got missed I will change them as part of that effort.