STYLE: Rename macro "slicer_include_once" into "superbuild_include_once"

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

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22750 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Ensure 'superbuild_include_once' works independently of caller scope.

By using GLOBAL property instead of a local variable, the file will
be properly "include guarded" even if included from within a function.

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

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22751 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Update CTK external project

$ git shortlog 46a1d6605..36fb628b1
Andreas Fetzer (11):
      Adding possibility to dynamically change the layout of the dicomTableManager
      ctkDicomBrowser uses dynamic table layout now
      Children of the QSplitter of the tablemanager are no longer collapsible
      Fixed missing update if new data is added
      Fixed bug where filter textfield's background remained black
      m_dynamic layout is now in pimpl and has read accessor. Some code cleaning
      Improved behaviour of dynamic layout: between 800 and 1024px window size use     vertical layout. If the window is bigger than 1024 switch to horizontal layout
      Renaming method for setting dicom database
      Not using const references when declaring a connection
      Setting dynamic table layout in ui file
      Proper naming of property with const read method

Jean-Christophe Fillion-Robin (3):
      Rename macro "ctk_include_once" into "superbuild_include_once"
      Ensure 'superbuild_include_once' works independently of the caller scope.
      Merge branch '418-support-use-system-option'

Julien Finet (1):
      Merge pull request #422 from AndreasFetzer/allow-dynamic-table-layout-for-dicombrowser-final

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

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22752 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Made file extension comparisons case-insensitive. Fixes #3511

Co-authored-by: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>

From: Andras Lasso <lasso@queensu.ca>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22753 3bd1e089-480b-0410-8dfb-8563597acbee