Merge pull request #1 from jzeyer/master

Fixed angle of the label position (Connection.cs)
Merge pull request #2 from jzeyer/master

Set connector source/sink to protected for save function
fixes for grouping
Merge pull request #3 from jzeyer/master

Fixed updateVisibleDesigneritems
Speedup fixes
Remove Default Template of Connector
Fixes with ID Handling
Fixes in Designer Canvas
Some Focus Calls are needed
Diagr. Designer fixes...