Allow cython 0.11.2 which works as well and is delivered by default with Ubuntu Lucid

Ignore-this: 20ebd46b3c342abde7a8152b6c90939d

darcs-hash:20100430143952-58252-49609221acca3874c666fea7be5700afac54f170
Update documentation

Ignore-this: 12e7a0fe5711cd67d412d3d457e50729

darcs-hash:20100430144216-58252-726f52bf1c2b8ab9fa2bae7b892c884d3c7c636c