We should be able to configure dispatch to run on its own sub domain or domain from within the config.

Summary: Based on some configs being set we build different dispatch URLs. Once you swap these configs the old links will stop working, but dispatch will read and generate correctly.

Test Plan: Tried with resource mapped dispatched on domain/subdomain/path/crazypath

Reviewers: brooke

Reviewed By: brooke

Maniphest Tasks: T45

Differential Revision: http://phabricator.cubex.io/D7