Remove MurmurHash from Beast and RippleD

The only use of MurmurHash in RippleD is to hash a public key to generate a hostid that is displayed to non-admin users in lieu of the actual system hostname. This pull replaces that with the classic [Jenkins](http://en.wikipedia.org/wiki/Jenkins_hash_function#one-at-a-time) hash, and removes MurmurHash from Beast.

Reviews: @ximinez, @josh-ripple, @vinniefalco
We could, but I don't really want to pull all the hashing framework for what basically turns a blob into a single word, especially considering that Jenkins has excellent properties and there are no security implications here.