Form submission doesn't have desired behavior

[elight]

Submitting a form within holygrail does not cause the subsequent page to be loaded into Johnson.

See http://gist.github.com/364103.

[elight]

This is because holygrail currently only does the equivalent of alias method chaining on the HTTP methods supported by Rails IntegrationTests. It probably similarly tweak the behavior of env.js to call back into Ruby through Johnson to update @__page.