Windows updater: Create backup and restore it on failure
Search libs in ../../PlugIns on OS X
Fix tox: url highlighting breaking the :tox: smiley

Fixes #772
Add more plugin search paths for OS X
auto away done right (fixes #751)
"overhaul" window title, fix #753
fix title editing issue, reported by "whoever"
Cherry pick most of #756
Minor bug fix:
The main window, will never be visible, when the user unchecked 'Show system try' and checked 'Start in tray'.
similar bug, when closing the window...
Cherry pick the first part of #762
using ToxID instead of bare QString + proper alias using during widget creation
Allow to change i/o audio devices without restart

Still needs to restart the calls for now

Fixes #713
Allow to change audio i/o device mid-call
Merge branch 'pr774'