Important for running behat tests per-module,
while stil keeping parameters like "base_url" configurable
without modifying behat.yml files in the modules own source code.
- Moved all extension-specific conf into its own configuration namespace
- Described configuration via PHP, and added default values
- Removed boilerplate config from README
- Made screenshot_path optional
- Configurable ajax_timeout settings
Note: The DI system plus the initializer+context combo requires insane amounts of code duplication,
will need to be looked at more closely (very little docs on that level of Behat extension available).
