Remove TAKEOFF from mission item fragment type list if there is more than 1 item in mission list
Allow LAND and RTL mission items to be set only in the end of mission list
Fix TAKEOFF item handling
Stop new mission items addition after RTL or LAND
Merge pull request #959 from alextel69/fix-takeoff-land-sequence

Fix TAKEOFF-LAND (RTL)  sequence

Closes #794
Merge pull request #960 from arthurbenemann/libraries-move

Moved External libraries to Libraries folder
Make Circle Item work again on AC 3.2RC3 or higher
Move Circle fragment to the right location
Fix paths broken by last commit
Merge pull request #970 from arthurbenemann/circle_fix

Circle Item fix
Version: Releasing version 2.6.1
Fix circle mavmsg unpack function
Changed default circle radius
Correctly unpack a mission with RTL
Merge pull request #971 from arthurbenemann/mission_items_fix

Mission items unpack fixes
NullPointer Exception fix on Editor

When opening the editor with a loaded mission a null pointer exception was being generated. This fixes the problem.
Merge pull request #972 from arthurbenemann/fix_editor_bug

NullPointer Exception fix on Editor
Remove old comment
Added FTDI library back, overwriting the open-usb-library
Add the FTDI library to the gradle build