Add 'find' command to cgpt, to search for partitions by UUID.

Review URL: http://codereview.chromium.org/2849040
diff --git a/cgpt/cgpt.h b/cgpt/cgpt.h
index 504e6dd..1ef74de 100644
--- a/cgpt/cgpt.h
+++ b/cgpt/cgpt.h
@@ -122,6 +122,7 @@
 int cmd_create(int argc, char *argv[]);
 int cmd_add(int argc, char *argv[]);
 int cmd_boot(int argc, char *argv[]);
+int cmd_find(int argc, char *argv[]);
 
 #define ARRAY_COUNT(array) (sizeof(array)/sizeof((array)[0]))
 const char *GptError(int errnum);