Split out HTTP specification configuration.

Move the HTTP specific configuration into its own class in preparation
for adding a lot more options.
Allow almost everything to be configurable for the HTTP configuration.

Nicks configuration and defaults from Dropwizard.
Merge pull request #14 from deverton/configurable-http

Configurable HTTP Settings
Fixed to pass HttpConfiguration in to connector factories
Fixed up some config and tests
Fixed HttpConfigurationTests
Fix the failing conn fatcory tests from the config restructure
Bumped for release 0.13.0