First steps toward activities in feeds

Removed actor from Note and Comment objects
Changed Feed and Inbox to handle Activity objects
Created Activity, Generator, UnknownObject classes
Merge branch 'master' into activity

Updated upstream
No content in deleted notes
More work on Activity, Generator, Unknown classes
Comment class: cleanup and fixes

Removed Comment.summary, this is now stored in Activity.content
Removed unneeded if["object"] in data statement, data is always the
object now
Added missing code in Comment.unlike(), Comment.delete()
Added Comment.liked, comment.deleted attributes
Fix typo in Unknown class
Changed Note class to work with Activity class

Removed Note.summary, this is now stored in Activity.content
Removed unneeded 'if "object" in data' statement, data is always the
object now
Clean up and fixes to Note class

Refactor code for posting activities to Note._post_activity()
Added Note.liked
Changed Note.deleted so when Note is deleted Note.deleted contains time of
deletion (was True)
Removed Note.serialize()
Removed Note.unserialize_to_deleted()
Comment class refactor

Refactor code for posting activities to Comment._post_activity()
Activity class, prettier __repr__

Activity.__repr__() now outputs <Activity: Activity.content> (stripped
of html tags)
Change __repr__ for Generator, Note, Person
Activity model docs
Merge branch 'master' into activity

Conflicts resolved:
	pypump/models/comment.py
	pypump/models/note.py
QnD docs compatible with activities
tutorial compatible with activities
Copy author from activity to obj

inbox/major doesnt have author set for posted objects, so we copy the
activity["actor"] to activity["object"]["author"]
Merge pull request #49 from kabniel/activity

Activity objects in Inbox