Improved map caching, waypoints and lines now colored with UAV colors, debugging map drag / zoom issue with waypoint lines

Map caching works now, uav following as well. Waypoint lines and some graphical tweaks needed, but its very close to an alpha release now

Runtime issues resolved, quick application startup and good runtime stats: 0.3% load in idle mode, 15% load showing map and UAS list. Map has a zooming issue, but should be resolvable

Fixed a bug where non-auto hold in the debug console induced 100% CPU load even when the widget was hidden

Working WP manager -> map waypoint updates. List reordering does not work yet. Next steps: List reordering, map -> WP manager updates, better waypoint graphs

Cleaned up serial port libs, activated mav visualization on map (still debugging), fixed standalone MAVLink generator

The MAVLINK_MESSAGE_LENGTHS macro can be used to detect mavlink
messages that don't have the expected length. It is done as a macro so
that projects that don't want to pay the cost of a 256 byte overhead
can avoid the check