Makes the dist dir and the dev time dirs used for resources configurable. This is a play side change and does not effect yeoman. That means if your web app results are not generates in /ui/dist then you can use this to change the location where play should look for them.

There are now two new configuration parameters that can be defined in play's application.conf -

1. yeoman.distDir - The directory where the resulting distribution from grunt build are saved. Defaults to "/ui/dist"

2. yeoman.devDirs - The directories to look for the files to serve during development. Defaults to ["ui/.tmp", "ui/app"]

Fixes issue #23