:core Add getURI to ResourceManager.
:core ResourceManager can now load using a Future.

Right now we just create a FutureTask<ResourceHandle> and call run()
before returning it. Later it would be better to throw it at some kind
of dedicated executor.
Discover URI.create()!
:core Don't worry about resource loading without a scheme.
:core ResourceManager now sets up gzip:// by default.
UnitTests now use maximum possible logging.
:core Fix NullPointerException in LogSink#log().
:pc Fix PcDisplay#setMode().

Typo was using mDisplayMode in place of the one queried.
Make setMode a public method of Display.
Display resolution can now be set from cofiguration file.

${GameName}.display.resolution will be checked for a value suitable for
Display#setMode().
Resource search path can now be set from configuration filee
Refactoring GameEngine.