Must memset structures before use.

This makes VehicleComponents reusable from core plugin without
requiring override of prerequisiteSetup

_finalize methods need information which is not available if all you
have is a mavlink_message_t

- Sensors summary now shows you how man compasses you have
- Fix for APM accel cal. Can only use first accel offsets.

Strings can be expensive to create, all the issues with allocation,
copy of the char members, conversion to UTF-16. QStringLiteral creates
one in compile time.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Also fixed problem with setup complete signaling after positive
calibration completed

There are many ways of iterating over lists in C++/Qt.
In the specific case of QStrings, it is known [1] that using
foreach with const references avoids the creation of new
QString objects in each iteration, reducing the time consumed
by the loops.

[1] https://blog.qt.io/blog/2009/01/23/iterating-efficiently/Signed-off-by: Anselmo L. S. Melo <anselmo.melo@intel.com>

This fixes rotate images showing up at the wrong time

- MultiVehicleManager is a Qml friendly replacement for UASManager
- Vehicle is a replacement for both UAS and AutoPilotPlugin