Merge branch 'release/v0.6.6' into develop
Added default name to objects which is it's type and id.
Added ConditionalSetter to properties, made GameObject's names only changeable when not already a child.
Implemented removeChild on GameObject and Scene.
Fixed bug where removed child would keep reference to parent.
Added RefGetter which returns a reference to the field.
Wrote a bunch of documentation.
Added check in tasks to make sure properties given to scheduleInterp are valid.
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.
Removed deprecated output module for next release.
Use x11 1.0.0 on Linux.
Fixed failing unittests.