clean up app settings

[alee]

settings are currently an ad hoc mess split across

• server
• shared
• client

look into unifying these in a cleaner way

on the server side look into unifying in-memory settings, env settings, redis settings, etc

[sgfost]

client settings

This was unused, removed in 10b3aa7

shared settings

6b2b4e9 and 4ce6bff deal with cleaning up and adding some new fields that are accessed by either the client or both the client and server

This module contains isDev() and similar helper functions to test what environment we're in. 75b2ddc replaced some instances of using server settings to check for devmode with isDev(). Makes sense to continue using these for consistency

server settings

2 modules for server-only settings: static and dynamic (using redis store). 75b2ddc moves lobby settings over to the dynamic settings.

These could still use some refactoring: either unifying or disambiguating