Don't inherit XAUTHORITY from the environment.

It's not especially obvious, and unpleasantly overloaded for the Xnest
case.  Typically this gives you a server that looks for its auth data in
the authority file you were using for the running X session, which
generally doesn't have an entry for the display you just started.

All the major dm's, and startx, pass -auth explicitly, so this shouldn't
cause too much upheaval.

dix/main.c

@@ -253,10 +253,6 @@ int main(int argc, char *argv[], char *envp[])
 
     InitConnectionLimits();
 
-    /* prep X authority file from environment; this can be overriden by a
-     * command line option */
-    xauthfile = getenv("XAUTHORITY");
-    if (xauthfile) InitAuthorization (xauthfile);
     ProcessCommandLine(argc, argv);
 
     alwaysCheckForInput[0] = 0;