Replace QMessageBox::warning by QGCApplication::criticalMessageBoxOnMainThread and removed unnecessary copying action

Added to ". Please provide a different file name to save to." to the error dialog

changed QGCApplication::saveTempFlightDataLogOnMainThread(QString tempLogfile) to enable overwriting files
existing file is removed before saving file (QFile::copy cannot overwrite files)

Reworking the layout of the "Return Home" Safety Dialog.

Repaired feature to save images from video downlink (fixes #1239)

Convert Firmware Upgrade to QML

Link Configuration Management

problem:
in src/ui$/HUD.cc copyImage(UASInterface* u): u->getImage() was called twice. The first called already erased the buffer.

changes:
src/ui/HUD.cc: copyImage(UASInterface* u): instead of getting the image a second time, we take the one we already fetched

I noticed that some times, the disconnect signal would get to the updateConnect button (tool bar) before the link was physically disconnected. That would cause it to count it as a still connected link and get the connect button logic out of sync.
While at it, added an interface to the UDP link to return its configuration instance. That allows the LinkManager to unlink it when disconnecting it.

This came through google groups and as the change is right where I'd been working, I added it here to avoid collision.

Fix Eigen includes

The goal of this first installment is to organize the code a bit so it's more readable,
clean up a bit of left over cruft, and manage link configurations (and links in general).

- Much simpler UI
- MVC style qml programming model

Fix SetupView to work with latest mavlink headers

Fix small logic error with NULL serial port.

Conflicts:
	src/AutoPilotPlugins/PX4/AirframeComponent.cc

Conflicts:
	src/qgcunittest/UASUnitTest.h

Put back commented out code

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

Updated MAVLink to include dense VTOL MAV_TYPE entries

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

Add missing qml modules to README

Support two param sets for calibration

Change SetupView to MVC model

Set Column component size correctly

Include support for both param sets

Fix setting the baud rate.

The parameters for calibration were changed in the latest master. QGC
needs to work with both. Hacked in for now, waiting on a true parameter
re-mapping implementation.

File extensions need consistency. Issue #1182.