Update playdoh-lib

91561d9 Update to Django 1.4.6  r=r1cky
198b178 Merge pull request #42 from dpoirier/update-tower
e8e6095 Update tower
77d2cc7 Merge pull request #36 from jsocol/arecibo
54be25a Merge pull request #40 from peterbe/upgrade-django-session-csrf
963f25c upgrade django-session-csrf for safer keys
d5db036 Drop django-arecibo.
Add .vagrant to .gitignore.

.vagrant folder is generated by the vagrant. This is must not be
tracked in the repository.
Fix mount folder name to prevent warning in the new version of vagrant.