ENH: Changed case of commands to lowercase to match our programming style.  Also added find_package command to find Tclsh.
ENH: Changed case of commands to lowercase to match our programming style.  Also added find_package command to find Tclsh.

matthieuheitz/TubeTK,matthieuheitz/TubeTK,thewtex/TubeTK,KitwareMedical/ITKTubeTK,LucasGandel/TubeTK,matthieuheitz/TubeTK,LucasGandel/TubeTK,aylward/ITKTubeTK,sumedhasingla/TubeTK,matthieuheitz/TubeTK,KitwareMedical/TubeTK,cdeepakroy/TubeTK,KitwareMedical/ITKTubeTK,LucasGandel/TubeTK,sumedhasingla/TubeTK,KitwareMedical/TubeTK,LucasGandel/TubeTK,cdeepakroy/TubeTK,cdeepakroy/TubeTK,thewtex/TubeTK,sumedhasingla/TubeTK,sumedhasingla/TubeTK,aylward/ITKTubeTK,thewtex/TubeTK,KitwareMedical/TubeTK,cdeepakroy/TubeTK,aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,thewtex/TubeTK,aylward/ITKTubeTK,KitwareMedical/ITKTubeTK,KitwareMedical/TubeTK