Load all libs AND all apps before binding configs

Presently, we load all libs and then bind their configs to values before loading any apps. This causes problems if an app needs to modify the config structure of a lib.

The only reason we do the binding in this order is to deliberately not load applications which require Hadoop. However, this behavior in itself is of questionable desirability. I propose we instead load all apps, and warn in the logs and via the config_validator system of Hue apps which require Hadoop if Hadoop is not present.