Large commit switching everything to using four words

This is a large commit adding a wordlist suitable for
encoding a geohash in four words. Associated to it
all the README and html pages need changing to make
this the default.
Rename to ThisPlace from These4Words

Trying to come up with a name that is independent of the
number of words we use to encode locations

Slight update to the word list.
More rude words removed
Merge pull request #21 from betatim/four-words

Switch to using four words