All 3 test program done.

1. forktest: ./forktest <delay> <fork|vfork|clone> <command line>
2. getcolors: ./getcolors <process name> <process name> ...
3. setcolors: ./setcolors <process name> <color> <process name> <color>
...

	new file:   forktest.c
	modified:   getcolors.c
	new file:   setcolors.c
Change Makefile PATH to CLIC machine

	modified:   Makefile
Modify warning line.

	modified:   getcolors.c
	modified:   setcolors.c
README for test programs added.
Change routine of error return; Protect around thread.

1. Instead of returning error code right after it occurs, use goto to put error handling together.
2. get_task_struct(thread) to protect thread coloring.

	modified:   kernel/color.c
Add usage message to test program.

	modified:   test/forktest.c
	modified:   test/getcolors.c
	modified:   test/setcolors.c