Use different port for each service.

Feanil/multiple vagrants

for edxapp, install python sandbox requirements into regular venv

Initial definition of the worker boxes in cloudformation.

Extract the app port numbers into the vars file.

The number of workers need a multiplier, which I missed in code review

temporary fix to allow some things that depend on this (like
drag-and-drop questions) to not break.  Also, this configuration
might be what trial installs prefer, anyway.

Make the condition on migrate_db a bit safer for using in var_prompt

Use ansible facts instead of facter.

The ansible_processor field provides a list of all hyperthreaded cores. Using
Jinja we can just get the number of cores on the machine by running length on
this list.

Use Relative pathes for ora and xqueue auth.json and env.json

Feanil/vagrant updates

Swap lms and lms-xml nginx ports and remove edxapp_sandbox.yml from vars_files because it no longer exists.

Putting migratedb in group_vars/all overrides any vars
in playbook files and so migrations never get run.

In regular runs it seems to have no side effect but fails for vagrant runs.

Feanil/ansible workers rebase

This also makes it easier to conditionalize it since it
doesn't need to be run on workers.