Added a reverse route context

This is made available whenever a PathBindable is implicitly required,
so that PathBindables can look at the context and get information about
the route they are binding.

The context contains all the fixed parameters for the route, this allows
an asset path bindable, that wants to put a hash of the asset in the
path, to lookup the value of the "path" parameter to find that the
assets live at "/public", for example.

As a method of testing/validating this, I created a new Assets.Asset class,
a new Assets.versioned route, and I modified the integrationtest project to
use it. I didn't actually implement the fingerprinting of the asset URL,
that depends on other things, but it's a start.
Fixed nested fillAndValidate

Fixes #1646
More TLS documentation

Add a quickstart section.
Add certificate generation section
Add ExampleSSLConfig.md
Add more to highlights section.
Add more to migration to 2.3
Add a section on testing SSL.
Add generation scripts so we can reference them via includes.
Merge pull request #2740 from jroper/reverse-route-context

Added a reverse route context
Merge pull request #1646 from jroper/1646-nested-validation

Problem with fillAndValidate on Form
Apply url.withQueryParams fix from #1861
Merge pull request #2745 from wsargent/fix-oauth-queryparams

Apply url.withQueryParams fix from #1861
Add links to Home.md, add reference to cert gen in ConfiguringHttps.md
Merge remote-tracking branch 'wsargent/more-tls-docs'
Removed dependency on scala-io
Merge pull request #2746 from jroper/remove-scala-io

Removed dependency on scala-io