Custom Transaction Middleware

[ksurya]

We might need a custom middleware to handle submissions that controls

1. database transactions similar to django.middleware.transaction.TransactionMiddleware which will get deprecated in Django 1.6
2. managing repository actions (create, commit, repos). If for some reasons, a exception occurred before "success" response and "after" creation of DVCS repo while submitting a snippet -- The repo is going to be saved in the static directory, and upon refreshing page, it raises Exception No changes observed as this refresh is considered as next-commit