Changed trophy logic to use Database

Made "TrophyManager" class and "compute_trophies" method.
Add the TrophyManager to Trophy model.
Create "iftrophy" at reviews/templatatags.py
In the method pull trophy data from database.


Implemented handling of many trophies.

Made abstract Trophy at reviewboard/accounts/managers.py.
Made 2 inheritance class(milestone, palindrome) from abstract.
Changed iftrophy method to send trophy_list data.
Changed trophy_box to use loop for trophy_list

Created unit tests and execute it.