this adds an option to select the mode of the joystick in the joystick
config widget. The mode sets the setpoint type which is sent when moving
the joystick.

I was unsure how to update the QwtPlotPrintFilter code, so I just commented it out with a FIXME.

Also deleted invalid line drawing options.

This reverts commit 5e2881ce.

Fix HIL link reconnect issues due to missing threading flag usage, warn user about missing config and take him to config view if necessary

espeak: provide string length with 0 character, fixes problems with qgc reading out strange values/chars at the end of the sentence

This way the delete happens on the right thread.

Current version was not as clear as it could be.

Most math and backend storage was floats anyways, so most of these changes just half the data copied during function calls without reducing precision.