Also fixed bug in loadStyle

Conflicts:
	src/uas/QGCMAVLinkUASFactory.cc
	src/uas/QGCMAVLinkUASFactory.h

No major functionality changes.

Both on the backend (replaced with DEFAULT view) and on the front end (removing UI menu items).

Includes removing an if-statement that should've been dead but was erronously applied to the following statement. Dead code = bad, if-statements without braces = bad.

This was deprecated on Febuary 3rd, 2014 and removed a little later. This finally completes that process.

SLUGS has maintained their patches out-of-tree for a long while now.
These will eventually get merged back in, but it'll be easier to evaluate them as fresh commits instead of modifications to this old & dead code, so we'll delete this for now.

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

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

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

Added documentation and clarified messages to the user.

This feature can be enabled at compile-time and documentation has been added to the README.

This allows you to add XY graph plots of any data.  For example,
x,y position data of a servo.

There's no need to create multiple signals - connect() is fine with
connecting styleChanged(MainWindow::QGC_MAINWINDOW_STYLE)  to a slot
with no parameters.

This fixes a bunch of bugs with setting the title for widgets, deleting
widgets, etc.  It also reduces the amount of code duplication, which is
always a good thing.

Change so MainWindow handles its own deletion, and deletion of other UI objects to allow for closing when the MainWindow is closed, regardless of if other windows are open.

Refactored QGC startup so that MainWindow::instance() is usable everywhere. This was required to get the styling working properly for ChartPlot.