PX4 mode cleanup

MockLink: Support multi-vehicle simulation

Move message area to top

Virtual joystick: Throttle no longer spring loaded to center

Mobile file dialog: Add logging

- Delay gps position for better testing
- Longer delay on home position

Height will shrink to fit small text heights

This allows you to arm

Settings real estate

Planned Home Position: Tweaks to wording to help with confusion

MapScale: Add support for feet/miles

Handle parameters at end of URL

Offline Map: Add preview and zoom numbers

Param load: Try initial request 5 times max

Offline map fixes

Trying to fix hdiutil create failure

Also don’t pop errors for initial request failure on generic vehicle.

- Max tile download count now handled here
- Fixed signaling problems

Turn on verbose in hdiutil

Save vehicle type for APM mock link

To debug travis failure

* travis-ci install gstreamer

* update linux gstreamer dependencies

* fixes #2540

* travis-ci doxygen to trusty

Fix MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES send/nack

Guider bar font sizing changes

Fix isSatelliteMap determination