remove libtaskmanager that creates conflicts with kwin scripting+6

--first attempt
task manager deprecated KWindowSystem in signals for kwin scripting

--in order to use the same codebase some tweaks had to been made
in order for the plasmoid to use the KWindowSystem but the
kwin script to use for the same signals the workspace object
update KWin script to use new signaling for windows
enable closeWindow from plasmoid space
fixed removeWindow code for the kwin script
Merge branch, update new closeWindow feature

Conflicts fixed:
	components/previewsmanager.cpp
	components/previewsmanager.h
	components/ptaskmanager.cpp
	components/ptaskmanager.h
	package/contents/ui/Activities2.qml