New development error page styles

Closes #448
Block guava here too.
Add left()/right() aliases to Pair.
Docs for configurable module.
Detach the HTTP URL builder from request spec.
Some more convenience to with.
Some tweaks to URL building.
Add convenience for get requests with no configuration.
Fix escaping issue with path segment patterns.
Merge pull request #463 from robzienert/new-error-styles

New development error page styles
Fix GitHub API requests for site.
Provide a throttle for generic operations.

Closes #449.
Upgrade to latest RxJava.
Fix problems with defer(), and add extra promise operations useful for diagnostics.
Add a mechanism for dumping out current executions.
Add API for decorating Response before sending.
Allow setting a read timeout for HTTP requests.
Ensure that cached promises resume subscribers on their execution.
Add ratpack-jackson-configuration module (#212)

This also includes making DefaultLaunchConfigFactory work properly based on LaunchConfigs.
Support for polymorphic config is included.
The jackson configuration factory doesn't yet support property/environment variable overrides.
Merge branch 'master' of github.com:ratpack/ratpack

Conflicts:
	gradle/dependencies.gradle