Wrote initial code for VCS interfaces for Pontoon.
Integrated new VCS backend with admin views.
Some refactoring and fixes.
Create a utils package to contain various utility modules

and related refactoring. The uitils package will contain modules like:
- vcs
- parser
for now and will be extended as needed. The aim is to keep the view layer
as lightweight as possible.
Move the core logic of updating from vcs from view to callable function.

This can be reused when running tasks in the background to update
local repositories from VCS.
Added task to fetch and update project's local data.
Merge pull request #11 from rtnpro/fetch_from_vcs

Repo sync.