Preliminary work on shadow maps for directional lights.
Merge branch 'develop' into feature/ShadowMaps

Conflicts:
	source/core/gameobject.d
Added some comments, little more work on directional shadow maps.
Merge branch 'develop' into feature/ShadowMaps
Set up rendering to shadow map, however the depth texture is all black.
Shadow map pipeline is all set up, however they don't work.
Merge branch 'develop' into feature/ShadowMaps
Minor changes, just need to fix problem with rendering the depth for shadow maps.
Moved config functions to the module scope, made tryFind nothrow and @safe.
Removed deprecated usages of old functions.
Moved constructor to module scope.
Moved constructor initialization to module scope.
Removed more deprecated Config usages.
Removed support for Vector3-Map, Vector2-Map, and Quaternion-Map because no one used them.
Some well needed cleanup in filepath.
Moved static constructor in lights into Light.
Centralized YAML constructors.
Use x11 1.0.0 on Linux.
Fixed failing unittests.
Merge branch 'develop' into feature/ConfigCleanup

Conflicts:
	source/utility/output.d