[Cmake] Set command

[Bill Hoffman]

I have just change the syntax of the SET comand:

  SET(VAR [VALUE] [CACHE TYPE DOCSTRING])
       "Within CMAKE sets VAR to the value VALUE. VALUE is expanded before 
VAR "
       "is set to it. If CACHE is present, then the VAR is put in the cache."
       " TYPE and DOCSTRING are required.  If TYPE is INTERNAL, then the "
       " VALUE is Always written into the cache, replacing any values "
       "existing in the cache.  If it is not a CACHE VAR, then this always "
       "writes into the current makefile.";

I have updated all of Insight, CMake and vtknew.

-Bill