reset window title every time we change the state of a subwindow to show the correct title

When maximizing a subwindow it remembers the title the mainwindow had before and resets it after unmaximizing/closing.
As the title might have changed due to a project switch, we have to reset the title again as it would else show an incorrect/old title.
Delay  Clear buffer on load, correct use of interpolation, reformat
Merge pull request #1479 from DanWin/title

reset window title every time we change the state of a subwindow to show...
change as of issue 1474
Merge pull request #1485 from curlymorphic/delay-1.1

Delay effect   Clear buffer on load, correct use of interpolation, reformat
Merge branch 'stable-1.1'

Conflicts:
	plugins/delay/delaycontrols.cpp
	plugins/delay/delaycontrolsdialog.cpp
	plugins/delay/delayeffect.cpp