Also handling the toggling of the various panes on the right side of the screen to match the current selected task.

Adjusted icons so they no longer contain a background.
Added *Exclusive* functionality to the RoundButton element.
Added OnClicked signal for the drop down boxes so I could turn off Add Mission Item and Home Mode.

Also moving the Plan View tool bar buttons into a Row element.

Replacing some icons, cleaning up help text, etc.

Also:
- Remove unused code

Also understand the concept of missions which cannot be edited

Remove nigh load/save

Plus more overall ui work

- New MissionManager
- Plumb MissionManager through MissionEditor
- Mission Editor supports get/set

- Restructured a number of MissionItem properties as well