Fix Middle Snaplines were not correct!
Merge remote-tracking branch 'remotes/sd/master'
Fix in Snapline - Middle Position is now drawn 1px aside
Code fixes in Line/Polyline Extensions
Items Control should have a Transp. Background so it can be used as a Drop Target
Merge remote-tracking branch 'remotes/sd/master'
Use "EnableAppXamlParsing" Setting, but default should be "true"
Merge pull request #630 from jogibear9988/master

Few fixups...