Changelog for xournal-render-0.6.0

0.2: 12 Dec 2011 * First public release 0.3: 18 Dec 2011 * Rename modules and make compatible with new xournal-types package 0.4: 25 Dec 2011 * Double buffer support 0.5: 15 Jan 2012 * ZipperSelect support 0.6: 12 Feb 2012 * Variable width support