compacted interpolation code a bit, more strictly following EAFP style
added programmatic interface
better pointers to documentation
fixed Markdown
fixed Markdown, cont.
In the special section with an empty name (headed "[]") where "global" attributes can be defined, you can now define a special attribute "prelude" that contains Python code which will be executed before production starts. It's still of limited use because ConfigParser does not preserve indentation, so you can't really write much Python, but it's handy for imports that you can then use in rules. Fixes #3.
Merge branch 'master' into feature/parallel