Separate install of SDL on OS X not needed

Delete any temp log file before each unit test case

New FactSystem

Allows parameter access from QML among other things

Bug fixes

So no need for connect window close test here

Also moved log file settings save check to mavlink protocol

Better QLoggingCategory support, fixed parameter list request

Also added/converted some logging to debug the problem caused by the
two parameter request apis.

This removes confusion as to whether you call UAS::requestParameters
(incorrect) or QGCUASParamManager::requestParameterList (correct) from
client code.

Param boot hang

Also only update the full tree one time once the full parameter list is
ready.

Mavlink log test

Conflicts:
	qgroundcontrol.pro

Previously link were just destroyed

This makes unit test output easier to read

Update README for QLoggingCategory usage

Flight mode setup