Don't crop gravatars on notification cells

resolves #96
Don't override note data on updateAttributes

`updateAttributes:` might get called with a partial response (e.g. only
id and unread fields included) and we'd lose data about the note.

resolves #100, probably resolves #101
Better position of switch in table cells

resolves #94
Make web view toolbar buttons white on iOS 6

resolves #93
Merge branch 'release/3.8.1' into develop
Fixes #102 - Added UIScreenEdgePanGestureRecognizer to screen (iOS 7 only) to handle making the sidebar appear with the off-edge swipe.
Bump version to 3.8.1