Trim down the module export list.
Document the 'Snap.Internal.Debug' module.
Merge pull request #201 from 23Skidoo/snap-internal-debug

Document the 'Snap.Internal.Debug' module.
Commit failing test for #203 (testing code not populating rqPostParams).
Make sure buildRequest populates the post parameters. Closes #203.
Document the 'Snap.Internal.Parsing' module.
Extend the Show instance for Response.

Show content length and the response body.
Document the 'Snap.Internal.Http.Types' module.