Specifies how much to offset the text on its horizontal axis. This property is used by the text symbol and is specified as a zoomable value. The value can be specified either in pixels or as a percentage of the font-size. Positive values move the text to the right side while negative values move the text to the left side.
Examples:
define text-offset-horizontal : 24 draw : text
draws the text at 24 pixels to the right of the original position.
define font-size : 8 text-offset-horizontal : 200% draw : text
draws the text at 16 pixels to the right of the original position.
