Fix white on text coloring

MissionItemStatus: Show seq nums, clickable selection

Slight increase to small size to fit label

More work on mission item indicators

Hide sequence numbers

Toggle Rally Point insertion on/off.
Highlight current Rally Point and current Waypoint.
Use tab bar instead of a row of radio buttons for selection (Mission, Fence, Rally).
Fix QGCHoverButton to handle proper checked state toggle.
Get rid of the many arrays used to define behaviors for the ToolStrip. They are now all defined within its model.
Fixed color for disabled text within ToolStrip (it was invisible)

Android done.

Plus more overall ui work

- Restructured a number of MissionItem properties as well