Verify pluto's enum tables

In addition to performing internal consistency checks, this test dumps
out and then compares the value of all enums.  This is to ensure that
enum changes don't have unintentional consequences - for instance
modifying an enum value that goes across the wire (as part of the IKE
or whack protocol).

To update run:

$ ./OBJ.linux.x86_64/testing/enumcheck/enumcheck > testing/enumcheck/OUTPUT.enumcheck.txt
$ git diff

and then carefully examine the changes
