Merge pull request #381 from eserkansozer/Help

#380 - Fixing multiple Help Window issue
Merge branch 'Invert-Colours' of github.com:eserkansozer/DownmarkerWPF
Hooked clickonce into the update button/view
Merge pull request #384 from JakeGinnivan/ClickOnceUpdateInApp

Hooked clickonce into the update button/view
Fixing icon
Fixed up update
Allowed different clickonce installers
Fixed clickonce product name
Update UI improvements
Small update viewmodel fix
More update style updates
Fixing cross thread exception
Fixed failing UI Test
Some more update tweaks
Small path changes
Update progress text did not disapear after update completes
Updated README
Merge from upstream