BUG: Fixed two minor issues of slice view annotations

* Fixed the error in the terminal No scalar values found for texture input!
* New slices that are added to the layout would have the same font
 settings as the other slices.

From: Alireza Mehrtash <mehrtash@bwh.harvard.edu>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23756 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fixed exception, added tooltip

Slice annotation failed with an exception when series time was empty.
Added tooltip to "Background DICOM annotations persistence" checkbox, as it was very difficult to figure out what was it for.

From: Andras Lasso <lasso@queensu.ca>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23757 3bd1e089-480b-0410-8dfb-8563597acbee
ENH: Fixed error message occurring after disabling SliceViewAnnotations

This commit fixes error message like this one:

Traceback (most recent call last):
  File "/path/to/Slicer-build/lib/Slicer-4.3/qt-scripted-modules/DataProbeLib/SliceViewAnnotations.py", line 596, in updateCornerAnnotations
    self.makeAnnotationText(caller)
  File "/path/to/Slicer-build/lib/Slicer-4.3/qt-scripted-modules/DataProbeLib/SliceViewAnnotations.py", line 838, in makeAnnotationText
    self.drawCornerAnnotations()
  File "/path/to/Slicer-build/lib/Slicer-4.3/qt-scripted-modules/DataProbeLib/SliceViewAnnotations.py", line 993, in drawCornerAnnotations
    sliceCornerAnnotation = self.sliceCornerAnnotations[self.currentSliceViewName]
KeyError: 'Red'

From: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23758 3bd1e089-480b-0410-8dfb-8563597acbee