Hotfix on 428

This is a small hotfix build which does the following:

- Adds client/server understanding of a ‘maintenance mode’ for the KAG API

- general error message improvement around certain API calls

- Fixes #606

- join-related API calls in the client and server now use persistent connections; server joins should be noticeably faster

A reminder - please read the previous post regarding Monday’s planned downtime to everything.

-FliesLikeABrick

edit: one more patch being pushed out that does the following:

- fixes a regression from the #606 fix above, this will be addressed more next week

- Server browser favorites now work again

- Quickjoin has been completely revamped.  this post explains the logic in the new one.  I know I’ll be using the quickjoin all the time now, it prefers favorite servers but has decent logic for selecting others as well.

- Fixed (workaround) sv_goldonly spam in server console in non-gold servers as well as the issue with wood blocks showing up for builders in non-gold servers.  A better fix for this will come next week (requires a netcode change so it will come with a build number change)