BugFix: Connectors not removing properly.
Circuit: Activate Ctrl-Z, Ctrl-Y, Del
BugFix: Meters Contexmenu issue.
BugFix: Relay strikes again.
BugFix: Crash deleting relay while circuit running.
BugFix: Oscope not removing correctly
BugFix: fixed. volt. not changing value properly.
BugFix: Switches not working properly
Oscope: Add filter property (and some cleaning)
