BUG Resolve issue with DirectorTest breaking RequestProcessor
Injector::nest and Injector::unnest are introduced to better support sandboxing of testings.
Injector and Config ::nest and ::unnest support chaining
Test cases for both Injector::nest and Config::nest
A service factory can be used for creating instances where a non-trivial
construction process is required. This is done by adding a `factory`
key to the service definition.
API CHANGE: Pass Object::create() calls to Injector::create().
API CHANGE: Add "RequestProcessor" injection point in Director, that Director will call preRequest() and postRequest() on.