expose all configuration settings to the environment; add option memcache.address to work with previous puppet settings


In the previous production config of customs-server, we overrode settings for:

    logLevel = info, 
    maxBadLogins = 10, 
    memcached = hostname:11211, 
    port = 7000

In the switch to convict, two problems:

1. maxBadLogins was not made available to be configured in the environment (or by config file). Once I had to change that, I figured all of them should be exposed. 

(Note for convict feature requests : in `rc` *all* config values are exposed to the environment).

2. the location of memcached was host:port, but in the port to convict, it is looking for a host and a port separately. I don't want to change the setting in puppet, so I just fix it here to look for a 'host:port' value first.