Added a video app that will take care of presenting videos

This is finished now:
- Cleans youtube urls
- Looks for youtube urls
- Fetch title from the url to name the video
- Basic model
Corrected misstakes and made sure is_youtube works
Added some exceptions to tools youtube part and made sure that the url cleaner works and throws exceptions when it should
Cleaned up the save code
Added tests for link_title (finalizing all tests) and added some improvements to tools.py, like the code for youtube_clean_title
- Added ModelTest and began writing some tests for video.models
- Renamed name to title
- url is unique
- Added support for youtu.be links (they are a little different)
Had to add kristina to installed apps in order for Django to recognize the templates directory
added a default homepage so I can test video tags
Broke out the discovery of video hash name to a separate function so it can be reused. Also, wrote tests for it
Wrote a first templatetag embedd_video that returns a link or an embedded video (in case it is a youtube clip)
Added vimeo support just because I can and it was fun