[Pulp-list] Api.update() semantics change

[Jeff Ortel]

All,

Be aware that I'm in the process of changing the xxApi.update() semantics as described 
here: https://engineering.redhat.com/trac/mgmt-integrated/wiki/PulpUpdateSemantics.  This 
involves changes to the Api.update() itself and the corresponding WS controller.  Also, we 
have a lot of unit tests that hack on model objects then call update() expecting it to 
just be stored instead of calling the proper API method (which was probably added after 
the test was written).  As I work through the unit tests, I'm replacing calls to 
Api.update() with the proper call if it exists.  But, in some cases there is none so I'm 
replacing with Model.get_collection().save().

I'm starting with the RepoApi because it's the poster child for this and probably doing 
ConsumerApi next.  I'll push after each API is done to minimize merge conflicts.

I'm also converting to using Model.get_collection() instead of BaseApi CRUD methods while 
I'm there.

-jeff