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.
Extend the 'Show' instance for 'Response'.

Now shows cookies.

TODO: Remove duplication.
Document the 'Snap.Core' module, part 2.

Now has examples for all functions except a small number for which it's hard to
produce an example in GHCi (timeout-related functions, 'escapeHttp').
Merge pull request #207 from 23Skidoo/document-snap-core-part-2

Document the 'Snap.Core'  module, part 2