Fix /updateserver
Fix /updateserver

This adds a bunch of minor fixes to /updateserver. The big one is that
we no longer stash untracked files, which should fix the problem where
it sometimes takes forever to update.

However, it seems like conflicting untracked files sometimes corrupts
the Git system?

    zarel@cytosine ~/W/psserver (master)> git rebase FETCH_HEAD
    Created autostash: abc06bdca
    First, rewinding head to replay your work on top of it...
    error: The following untracked working tree files would be overwritten by checkout:
        server/chat-plugins/help.ts
    Please move or remove them before you switch branches.
    Aborting
    fatal: Could not detach HEAD

    zarel@cytosine ~/W/psserver (master|AM/REBASE)> git rebase --abort
    error: could not read '.git/rebase-apply/head-name': No such file or directory

I couldn't reliably reproduce this, unfortunately, but I've switched to
`git rebase --no-autostash FETCH_HEAD` to be safe. File conflicts
are really rare in general, so I don't think that needs to be a
blocker.

svivian/Pokemon-Showdown,svivian/Pokemon-Showdown,Zarel/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,Zarel/Pokemon-Showdown,sirDonovan/Pokemon-Showdown,sirDonovan/Pokemon-Showdown,svivian/Pokemon-Showdown,sirDonovan/Pokemon-Showdown,svivian/Pokemon-Showdown,svivian/Pokemon-Showdown,Zarel/Pokemon-Showdown