This reverts commit af0589b2.

Fix execution context of thread routines - note that this is not quite the architecture the Qt folks intended, but as they admit its the consequence of their architecture.

Avoid evil port config for CDC devices altogether, non-CDC devices (unknown devices) should be unaffected

Do not configure the port if talking to PX4 units (since USB does not know anything about baud rate)

Removed completely unused variables. Ifdef’ed out variable which is
referenced from commented out code.

Fixes Issue #542

This patch fixes a bug that display 0 for distances to waypoint more
than 10km.

Besides that, it also homogenize the naming of the label to
"distToWaypoint" instead of "distToWP". Old configuration files (in
home directory), should be hacked or removed in order to see this
change.

Signed-off-by: Paul Chavent <paul.chavent@onera.fr>

Also commented out noisy serial link error output

MainWindow::loadDataView has been commented out for 9 months now.
Removed commented out code instead of leaving cruft in.