Basic save functionality in abstraction layer

[pobocks]

It's desirable to make it convenient to alter and save JSONModelObjects up to the database. Proposed API something like:

# On JSONModelObjects
def save(self, refetch_if_stale=True): 
    pass # signature, body omitted

my_obj = aspace.repositories(2).resources(1)
my_obj.dirty # False
my_obj.title = "a title"
my_obj.dirty # True
my_obj.save() # saves to ASpace
my_obj.dirty # False

[pobocks]

This is gonna be waaaay more complex than I initially thought, because nested objects.