0.1: 17 May 2011
  * initial preview release

0.1.1: 18 May 2011
  * fix tic-tac-toe example

0.1.2: 18 May 2011
  * link to new website

0.2: 3 June 2011

  * add Typeable and other instances for Cairo type

  * generalize Result type to (IO (), Render ()), so programs that
    don't want to generate a file but just want a Render operation
    (e.g. to use to paint a gtk window) can use the second component.

  * add support for opacity attribute and path clipping