Fixing Examples Makefiles problems

closes 3751

- The real issue was with the capitalization of the prerequisite in the main Makefile.  That should take care of the race conditions. 

- To get rid of the override error, I simply cheated make.  Each of the Makefiles now have a variable override of "TEST" which is what is used to define the actual test target.  That way I can define what that target does without using double-colon rules or overriding.