Allow preset dx and dy values on entity.
Fixed bug to allow render-image to be added after entity is created.
tiled-loader can now accept entity names as defining entity type.
Modified dom-element's parent property to search entity's main DOM element for the appropriate id before using document.getElementById since the current scene may have a matching element id with that of a loading scene, causing elements to be added to the wrong element.
Added "if(this.stage)" check due to entity not having a stage if it was destroyed in the same game loop.
Merge branch 'master' of https://github.com/gopherwood/Platypus