ENH: add transactions middleware

1. We need a db transaction middleware to support snippet submissions!
without this, data is saved into db even when errors are raised during
submission
2. Please refer https://github.com/scipy/SciPyCentral/issues/132
3. This middleware mostly important for submission app

Note: This middleware is deprecated in Django 1.6 but considering that we
are still upgrading to 1.5, its a long way ahead!
ENH: add title to feed links

Add title to feed urls on right-side-bar
ENH: change show-entries.html page title

1. add underline
2. apply gray shade to {{extra_info}}
3. remove unwanted div
Merge pull request #143 from ksurya/submission-fix

ENH: add transactions middleware
Merge pull request #145 from ksurya/design-fix

ENH: Design fix