Jarv/xserver updates

Jarv/certs role

creating syslog writable log dir

always run the create xqueue user task

Update the jenkins worker to use the mongo role.

The common role also has to be included because vars that were previously being set in group_vars_all are now in
the slimmed down common.

Jarv/fix shell commands

adding role for importing the demo course

Certain tasks (like generating grades) require a great deal of

memory that isn't properly freed up. This creates a queue for such
workers so that we can give them different configuration settings
-- in this case, setting CELERYD_MAX_TASKS_PER_CHILD=1 to force
workers to die after they process one job. Because these jobs tend
to run for hours, the overhead is not a big deal.

Common refactor - Applies changes to edx_sandbox

some forum deploy tasks missing the deploy tag

Jarv/common refactor