Added code for ODT export.

I added the code for the ODT export.  ODT export will fail if the stack can not be created or if the plugin ODT is not available. In such a case the ODT render function returns false.

If the plugin ODT is older than version 12.10.2014, then the helper class CSSColors is not available yet. In this case a default color value will be used if a CSS color name is used as a param for the typography plugin.