`master.ui.port` and `worker.ui.port` were never picked up by SparkConf, simply because they are not prefixed with "spark." Unfortunately, this is also currently the documented way of setting these values.

Author: Andrew Or <andrewor14@gmail.com>

Closes #1779 from andrewor14/master-worker-port and squashes the following commits:

8475e95 [Andrew Or] Update docs to reflect changes in configs
4db3d5d [Andrew Or] Stop using configs that don't actually work