Various fixes for skin styling.
Show the recording time
Remove milliseconds
forbids empty argument
Remove unnecessary alignment
fix merge conflicts - recording_time & master
remove qtime logic from dlgrecording - add counting of samples
move sample counting logic from dlgrecording to enginerecord + cosmetic fixes
replacing ControlObjectThread for ControlObjectSlave in enginerecord
Merge https://github.com/mixxxdj/mixxx into recording_time
remove unnecessary var m_cueSamplePos from enginerecord
cosmetic fix: recorded instead recored
use the same logic of couting duration in cue writing
Merge branch 'master' of https://github.com/mixxxdj/mixxx into recording_time
cosmetic fixes + emit changes per second
Merge branch 'master' of https://github.com/mixxxdj/mixxx into recording_time
Merge branch 'master' into fordemo-backport-clean

Conflicts:
	src/widget/wpushbutton.cpp
Allow the use of properties to change styling of pushbuttons

CSS can be used that looks like:
(hash)MyButton[displayValue="0"] { }
Move the unpolish/polish calls outside paint, because they call paint.
Merge branch 'master' of https://github.com/mixxxdj/mixxx into recording_time