Add QHandleManager template and test

With: Paul Lemire

Change-Id: Id269fd051a6a6b4f23a733c8123f11bb63e80aa7
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
QResourcesManager

QResources manager adapted to work with Sean Harmer's QHandle and
QHandleManager.

Change-Id: Ia2d60c93b72913194bbd04e064a5457ff1a091b7
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Fix INDEXBITS in QHandleManager, QHandle

QHandleManager worked only when INDEXBITS was set to the default value 16.
This is corrected now so that a QResourceManager<T, 4> created a
QHandleManager<T, 4> which provides QHandle<T, 4>

Follow up commits will follow for the refactoring of QResourcesManager into
subclasses that can implement their own dedicated memory allocation scheme.

Change-Id: If3b3fb43ae1c9473d9777cf9ba984ba37a65cfa9
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>