vagrant-dev-env:  Make sure all installed python modules are available

Modules in virtualenv are used by www-data, but installed with root.
This is results in incorrect permissions in some modules like:

/opt/edx/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg-info/top_level.txt

which by default is only readable by users from the same user/group.
vagrant-dev-env: Add syncdb to developer configuration