Rename the "Close" working set button to "Stash"

This should make it more clear what it does, esp. that it does not discard
the set.
The action is already connected, don't do it twice

Othewise it was jumping twice on every action trigger.
Also don't store it as member, it's unused.
SourceFormatterStyle: Pass const& instead of ptr

This is a value-type
VariableToolTip: Improve appearance

Use QPushButtons for the actions

BUG: 332968
Remove unnecessary initializations
Make it possible to tell the project that it's being reloaded

So far, we had the logic that tells whether a project is being reloaded
duplicated between the cmake manager and the project* classes.
This patch makes it possible to the plugin to delegate the responsability
to the IProject instance by telling it what's the job responsible for the
reload.
Merge remote-tracking branch 'origin/master' into frameworks

Conflicts:
	shell/workingsets/workingsettooltipwidget.cpp
Minor: Debug--
Fix invalid signal/slot connections
Fix standardoutputviewtest
"Fix" shell-uicontrollertest

Gives this more time to show the UI