Dashboard 2.1

Due to the inconsistent and unpredictable behavior plus the license of packery, I have replaced it with a different library called gridster (http://gridster.net/). The change required altering the way the tables are stored in the DB so I created a migrate script to convert them. Unfortunately some of the tables positions will be reset but their widths should stay the same. The command to run it is:

python manage.py migrate_dashboard_searches

There is one trade-off to the new library, it seems to be less responsive than packery was (especially in FF) but overall I think it is a large improvement.

Along with this change, I have included another feature of being able to directly add a saved search from another dashboard to the one you are currently on. To do so click the new button in the button bar: 
![new_button](https://cloud.githubusercontent.com/assets/5447264/5188414/b0abcd42-74a2-11e4-8a3a-d1c0532d9474.PNG)

Also you can now easily switch which dashboard a search is saved to by dragging it's row and dropping it on a different dashboard.