Add appdata file
Add comment to .desktop
Fix 'Recent Changes' dialog placement

On multi-monitor setups this was messed up, especially if one monitor
is below the other. Now get dimensions of 1st monitor and place based
on those. Preserve existing (strange?) placement logic.
Use SetDefaultSize rather than SetSizeRequest to allow resizing.
update News.txt with 1.2.0 release date
update README with a more explicit note about the Git dependency.
Merge pull request #1393 from comzeradd/appdata

Add appdata file
update Appdata file descriptions. #1393
Merge pull request #1397 from leighman/master

Fix 'Recent Changes' dialog placement
linux eventlog: Minimum size for the window
statusicon: Add temporary hack to always reflect the right status
linux setup: Show download speed when adding projects
windows setup: Tweak position of progress label
build: Use GTK+3
Temporarily disable dependencies that require GTK+2
ui: Port all the things to GTK+3
Re-enable notify-sharp
eventlog: Fix temporary warning
setup: Fix some style issues
setup: Remove debug lines
about: Fix scaling when using different fonts and a11y mode. Closes #1211