Fix crash in VC when adding widgets.
I added Qt::QueuedConnection to some connect() calls. I don't understand the mechanism, it seems to work.
Please review and/or extend to other menu actions.

I got the idea from https://bugs.kde.org/show_bug.cgi?id=311167

Fixes #120.
Merge pull request #146 from janosvitok/issue120

Fix crash in VC when adding widgets.
Initialize width and height of VCFrame. Harms no one
Revert Function default duration (for now) as causing unit test failures
Fixed crash when trying to display the audio editor on a non existant file
Apply intensity only to channels that can fade

VC Cue list improvements but still a lot to do for crossfade
Disable editing of non-editable tree columns
First working implementation of a completely rewritten runner for Cue Lists.

With this is will be possible to run more than one function at the same time (@TODO)
VC Cue List crossfade starts to work. Need to complete some visual aspects
Set tooltips of VC Cue list buttons
VC Cue list crossfade does its job !
VC Cue list crossfade can be controller with an external controller

Updated translations
Bump to 4.4.0

Improved Cur list runner to pass unit tests
Updated changelog
Attempt to reduce CPU usage of Show Manager playback
Documentation updates - typo, and description of USB DMX modes.

The description is incomplete.
Fix crash when sliders of an empty cule list are moved down to zero.
Documentation updates for the new functionalities
Extra check on spectrum bars number during configuration
Fixed Audio spectrum bars number change and configuration dialog reject
Audio triggers now saved/loaded from a project

Fixed various potential memory leaks
MasterTimer frequency can be set from a configuration parameter

Updated and unified documentation of manual tuning of configuration parameters