A few cvar default suggestions

Consider this a suggestion in the form of merge request.

First, remove the axis bindings for item and drift. While these work decently as defaults for xbox controllers, they turn off many other players that use dinput based controllers, such as the common playstation controllers. It manifests as an issue where if using a playstation controller (and some others) that the item axis default maps to the right stick.

Folks will play for the first time and have their items going off randomly, without any idea why. We get a number of these folks asking about this in #tech-support over time. I had a friend have an issue with this the very first time he played kart and it was frustrating for them until I figured the issue out. I think removing the binding default will benefit more folks than folks it will harm, item and drift are still bound to bumpers on xbox by default.

The second part of this is a couple adjustments to a few cvars regarding netgames. We set maxsend and downloadspeed to max, to make it more useful for the folks that cant setup an http source or don't know/ask how to set up or use the community one.

We increase the defaults for nettimeout and jointimeout from 3 to 6 seconds. I know some players who load slowly have issue where they timeout trying to join some servers, and increasing these timeouts typically makes this less of an issue. I know Tyron has his servers with these set at MAX (60 seconds) without issue, but I've been more conservative and this is what my servers use. Also resync attempts down from 5 to 2, since I value smoother gameplay over successful resyncs. I also believe that if someone can't resync after one or two attempts they probably won't resync.

If you don't agree with all of these changes, let me know and I can separate the ones that are wanted into a separate request.