Add helpers helpers for HTTP methods taking params

Add versions of `post`, `put`, `patch` which take parameters in a
form-encoded format. These functions take a list of key/values, generate
the bytestring body, and supply the requiste headers for WAI.
Remove non-conforming request-with-parameter functions

HTTP 1.x does not handle form-encoded query parameters with empty values
or methods beyond GET and POST. This leaves only the `postWithParams`
function as a useful addition to Hspec.Wai
Update .ghci
Fix typo in spec description