Merge pull request #205 from 23Skidoo/document-snap-test

Document the 'Snap.Test' module.
Add links and escape special characters.
Fix Haddock comment rendering.

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Add links.
Don't mention enumerators in the documentation.
Document a workaround for a bug in Haddock.
Add examples for 'route' and 'routeLocal'.
Add examples of access to response/request data from Snap monad.
Document the 'Snap.Core' module, part 2.