Replace 9 seperate valueChanged() signals with just 1, and remove the resultant tons of code duplication

* The "Simulation" option is now not selectable.
* If the link is a simulation, then you can't change it to a different link type.
* The OPAL option is not shown if support is not compiled in.
* Fix the buddy, tab order and accelerators in the GUI.

This crash could be reproduced by starting QGroundControl, switching to
plot, then clicking the "Symmetric" checkbox.

- MAV resets the RC_DSM_BIND param back to 0 automatically but QGC
doesn't know about this and thinks the parameter hasn't changed when the
pair button is hit a second time. Since it thinks the param has not
change, it doesn't transmit the update.
- This implements method to allow to optionally force QGC to send the
update. By default it does not
- Also added copy statements to include the two missing DLLs
(QtDeclarative and QtScript) automatically as part of Windows build.