*: stop using 0xBEEF

Using 0xBEEF is annoying in examples because it makes it makes it look
like the user can use ascii or something. In the Procfile use
0x0,0x1,0x2,etc and use 0xBAD0 in test.
Merge pull request #1038 from philips/vegan-etcd

*: stop using 0xBEEF
Procfile: add a comment on how to use this