Android: Fix typo
Android: Add a disarm button to the FlightActions fragment
Core: When disarming set the mode to LOITER

So the user can arm the copter via the tablet later, which is not possible if the copter is on LAND or RTL modes
Core: Move Takeoff code to GuidedPoint

Since it's part of the guided flight mode
Core: When doing a takeoff command update the internal fields of the Guided variable

Mainly the altitude should be set correctly.
Merge pull request #1099 from arthurbenemann/ActionButtons

Actions Buttons improvements: Tablet only flight