Moving __storm_table__ set to metaclass.

* __new__ is called before every time the instance is allocated,
  not everytime the class is allocated[*]
* move __new__ storm_table setting to metaclass, and remove old function.
* try to do something about those shitty int_keys, unicode_keys, ...
  but then decide to give up.
  WTFs are:
   - Pickle() object treated as unicode.
   - wizard_completed not in bool_keys
   - update() ACCEPTS KEYS NOT PRESENT AAAAAA
  It feels to me that we need an internal update and one to be used by views.

[*] to better explain this choice to gl devs that will stare at me::
>>> class Meta(type):
   ....:     def __init__(cls, name, bases, attrs):
   ....:         print 'hey!'                                                                                                                                                                                                                 >>> class Foo:
   ....:     __metaclass__ = Meta
   ....:     def __new__(self):
   ....:         print 'ohi!'
hey!
>>> Foo()
ohi!
>>> Foo()
ohi!