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
typo
Print out same error content message only once if it stays the same + fix typo
Merge pull request #52 from RouxRC/patch-1

Fix typo in QnD docs
Merge pull request #53 from RouxRC/master

Print out same error content message only once if it stays the same + fi...
Fix spelling mistake in readme
Update AUTHORS.md
Merge pull request #54 from RouxRC/patch-2

Update AUTHORS.md
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()
Fixes problem where Image was expected summary, infact it's content
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)
Fix problem fetching comments on notes
Version bump for pypi