Handle changed submodule URIs.
Handle changed submodule URIs.

As it turns out, if you change a submodule's URI (e.g. from the main
repo to your fork), you need to run "git submodule sync" before
updating your submodules with "git submodule update". Otherwise, the
changed remote doesn't take effect.

Fixes #5.

engineyard/engineyard-serverside,engineyard/engineyard-serverside,engineyard/engineyard-serverside,engineyard/engineyard-serverside