VIX-226 added serial port retry logic to controllers.
Merge Tony E's serial port logic changes for controllers.

Conflicts:
	Modules/Output/FGDimmer/SetupDialog.Designer.cs
	Modules/Output/GenericSerial/Module.cs
	Modules/Output/GenericSerial/SetupDialog.Designer.cs
Fixes for sequence/editor handling:
- an editor now specifies a Type of sequence that it loads, not an extension (so decoupled from the file that's being opened, as it may be imported and converted)
- a Sequence type now provides the file extension that it wants to be saved with, and the SequenceType module refers to that
Remove the Vixen2xSequenceImporter project; it's been merged with the Vixen2x sequence type
Vixen2x: added a 'status' dialog showing what channels will be mapped. Barebones and basic, but gives some sort of user interaction, at least.
Vixen2x: minor addition for null ElementNode handling in the channel mapper.