added elexol modules
Merge branch 'master' of https://github.com/sall/vixen

Conflicts:
	Vixen.sln
solution file with elexol controllers
New output plugin for the Elexol Ethernet controller
Merge remote-tracking branch 'remotes/eberletj/master'. Manually fixed up the Vixen.sln conflict.
Fix up a few config and project issues with the ElexolEtherIO project.
Remove the ElexolUSBIO module in the solution for the time being (since there's no code committed for it).
Fix release notes copy destination (quotes).
Correct bug that allows nodes to become abandoned if they are converted from a group back to a element. Update migrator to fix prior broken configs.