Make the new scenario activation API more REST
Handle exceptions in "end" events better

* When an exception was thrown inside the "end" event handler for
  a response (eg. when an assertion in a response object test
  failed), the head got confused and "corrupted" the response
  body.
* So, only set the unhandled exception response (status code 500
  and body set to the stack trace) when the response hasn't ended,
  but re-throw the exception instead.
Trivial fixes/tweaks (jshint, wording, whitespace, rename variable)
Parse request body inside the Request object

* What was I smoking when I decided to do it outside?
* Also, it seems it's not needed to catch exceptions when parsing
  with qs?
Normalise HTTP method names to uppercase
Admin REST API: First step (head API)
Admin REST API: Plugins
Admin REST API: Scenarios
Admin REST API: expose list of plugins and test results
Admin REST API: Explain the deprecation logic for a URL
Update copyright year in README file
Tiny clean-up
Set the Content-Type for all REST API URLs
Drop /scenarios/testResults.json, just use /rest/test-scenarios
Make the "type" an object property, doesn't work otherwise
Remove unused code
Demoronise some admin plugin template code
Make robohydraHeadType code a bit clearer
Show the name of the current hydra in the admin UI
Add a simple example of a summoner