ENH: Update to DCMTK-3.6.1_20161102

Suggested-by: Andriy Fedorov <fedorov@bwh.harvard.edu>
Tested-by: Christian Herz <christianherz1985@gmail.com>

$ git shortlog efe1a17..DCMTK-3.6.1_20161102 --no-merges
Jan Schlamelcher (11):
      Fixed wrong usage of checkStringValue() in dcmpmap.
      Several fixes for dcmpstat.
      Fixed 32 vs. 64 bit problem in dcmqrdb.
      Fixed using third party libraries with MinGW.
      Fixed a problem with a previous commit.
      Added OFvariant implementation for C++11.
      Added API documentation for OFvariant etc.
      Updated Makefile dependencies.
      Updated man pages for new development snapshot.
      Updated DCMTK_ABI_VERSION for new development snapshot.
      Updated CHANGES.361 for new development snapshot.

Joerg Riesmeier (3):
      Made clear that options +/-Uo require +Ug.
      Output debug messages when updating attributes.
      Added readXML mode that accepts empty/missing UID.

CMakeExternals/DCMTK.cmake

@@ -24,7 +24,7 @@ if(DEFINED DCMTK_DIR AND NOT EXISTS ${DCMTK_DIR})
 endif()
 
 if(NOT DEFINED DCMTK_DIR AND NOT ${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
-  set(revision_tag efe1a177eac040b6d41aae0db7714cd970e12bc5) # DCMTK-3.6.1_201610.12
+  set(revision_tag "DCMTK-3.6.1_20161102")
   if(${proj}_REVISION_TAG)
     set(revision_tag ${${proj}_REVISION_TAG})
   endif()