Merge tag '1.2.0' into develop

Addition of example web server, addition of back-off behaviour for requests for full hashes and a bugfix with the calculation of host hashes for parent domains.
Embed hat-trie code from https://github.com/dcjones/hat-trie
Reflect embedding in readme
Remove hat-trie from travis build file
Merge pull request #5 from rjohnsondev/feature/embed-hat-trie

Feature/embed hat trie
Merge branch 'release/1.3.0'