Build dir not set when using cmake 0.1 as per docs

[marcbrevoort-cyberhive]

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I had some trouble getting things to work with cmake 0.1 which - contrary to the current version - does not set the working dir before the final build step. Upgrading to 0.1.42 seems to have resolved my build problem. I would suggest upgrading the documentation to point to this working version as well so as to save people some time hunting down an issue that's already resolved.