Add pagination for user's events

- When there are more than 5 events under Past, Upcoming, and
Recommended, the user can now paginate through the events via next page,
previous page, and clicking on a page number.
- The count of Recommended events will now show the correct value when
there are more than 5 events
Bugs #337 (new menu item), #464 (link shortening)

Bug #337: The "Events" drop-down menu will now have a new item that
links to the page that lets the user create a new event. This menu item
appears only when the user is logged in.

Bug #464: When sharing an event through twitter or facebook, the event
url is now shortened through bitly.
- You'll need to create two environment variables: BITLY_USERNAME,
BITLY_APIKEY
Add pagination for user's events

Changed tabs to spaces
Revert "Bugs #337 (new menu item), #464 (link shortening)"

This reverts commit 50b684cdf3116f26a198921c13bf0f171c9e0d34.