Add 'prioritize' command to cgpt tool.

This lets us reorder the priority of all the kernel partitions with a single
command, instead of a bunch of complicated and error-prone shell script
logic.

Change-Id: I21d39763ec5a748488d5319a987bcfe7c34ce4d0

BUG=chromium-os:9167
TEST=manual

In the chroot, do this:

cd ~/trunk/src/platform/vboot_reference
make
make runtests
make clean

Everything should pass.

Review URL: http://codereview.chromium.org/5352005

firmware/lib/cgptlib/cgptlib.c

@@ -9,11 +9,6 @@
 #include "gpt.h"
 #include "utility.h"
 
-/* global types to compare against */
-const Guid guid_unused = GPT_ENT_TYPE_UNUSED;
-const Guid guid_chromeos_kernel = GPT_ENT_TYPE_CHROMEOS_KERNEL;
-
-
 int GptInit(GptData *gpt) {
   int retval;