Update hacking with correct git push command.
Add the user stats api endpoint.

- Add docs for the new endpoint
- Add the api endpoint to return user's bookmark counts

This is a cleaned up merge from Sambuddha Basu. All credit to him and his
work.
Add ability for user to delete all their bmarks.

- Added model test for deleting all bookmarks
- Added view tests for delete_all_bookmarks
Only require date for user stats.

- Fixes issue #329.
Make sure export sends bookmarks w/o tags.

- Fixes #331
explicitly create python2 virtualenv
Merge pull request #336 from dyladan/makeenv

explicitly create python2 virtualenv
Add user stats page to display bookmark counts.
fix url alignment on edit page
fixed : bookmark count for users incremented