Created 2 methods for setting label for mini-preview widget. The first is "by name...

Created 2 methods for setting label for mini-preview widget.  The first is "by name" and the second is by template.   This second method allows us to use a label's local template, even if its name is not an exact match with an existing template's -- can occur if templates are renamed between versions or if a label uses someone else's custom template.

git-svn-id: https://glabels.svn.sourceforge.net/svnroot/glabels/trunk@377 f5e0f49d-192f-0410-a22d-a8d8700d0965