First batch of renaming test -> scenario
Second  batch of renames
First batch of renaming "test" to "scenario"

At this point we still keep separate "test" and "scenario"
versions of the data, but all tests pass.
Trivial refactoring: rename variable
Adapt the admin interface to the test->scenario rename
Simplify the scenario admin interface

Drop the "Actions" column and make the "State" column contain
buttons to toggle the state (much like the recent change in the
head admin interface).
Show a message on admin UI when no scenarios are available

* While at it, fix a bug that made the "*current-scenario*"
  pseudo-plugin end up with a broken internal structure.
* The fix needed a small refactoring of plugin internal
  structure code to be sane.
Fix and clean-up examples

* Adapt and rename the scenario example
* Fix "simple-streaming" example (was using old API for events)
Trivial clean-ups (mostly jshint)
Allow whitespace in scenario names
Add simple front-end dev proxy in the standard distribution
Allow skipping config file and load plugins on command-line

* Add -n command-line switch to skip configuration file loading
* Add -P command-line switch to specify an extra list of plugins
  to be loaded
* These two switches combined allow someone to try out and use a
  plugin without having to write a configuration file, eg. use the
  now-standard front-end developer proxy without having to learn
  much about RoboHydra or write any configuration file