BUG: Fix for crash in vtkImageResliceMask (#3301)

* Force the output image and mask extent to be the same to avoid the possibility of mismatched extents
* Add a NULL-pointer check after the backgroundMaskPtr setting to prevent application crash (worst case it causes partial screen refresh)

From: Andras Lasso <lasso@queensu.ca>
BUG: Add support for selecting No module in module selector toolbar

Because the NoModuleAction is not observed by ctkMenuComboBox, the
toolbar shall clear the text of the current action manually.

In case the previous action was the NoModuleAction, it would not
have been added into the history, however it shall still trigger
the moduleSelected signal to show in the module panel.