New release: 1.1.0

Just pushed and tagged on master :) I'd normally now write a looooong wall of text here about what's in there, but that's what the shiny new CHANGELOG is for in the future, so read it up here: 

  https://github.com/foosel/OctoPrint/blob/1.1.0/CHANGELOG.md

Update instructions can be found on the Wiki:

- OctoPi: https://github.com/foosel/OctoPrint/wiki/FAQ#how-can-i-update-the-octoprint-installation-on-my-octopi-image
- manual install: https://github.com/foosel/OctoPrint/wiki/Setup-on-a-Raspberry-Pi-running-Raspbian#updating--switching-branches