wscript: Default to jackdbus, enable dbus autolaunching

When 14 years ago --dbus configure option was added to wscript,
I was affraid that deployments of builds configured with defaults will
get broken, so I kept jackd daemon enabled by default.

Since then the mixed jackd+jackdbus deployments had happened -
a bunch of distro packagers ignored the upstream configure time
warning and the JACK2 project suggested packaging approach that
strongly discouraged such deployments.

Another issue that has proven problematic is the configuration of
autolaunching capabilities. For the sake of robust jackdbus
deployments, I'm also enabling dbus autolaunching. This will ensure
that jackdbus daemon will work as designed and expected to behave.

This commit is first of several that will remove the jackd code
from the source tree. Then, jackdbus will be buildabe from
dedicated repo+branch for jackdbus source code only, to be built
against jack2 (with jackdbus stuff removed), installed system-wide and
libjackserver accessible through pkg-config.

wscript

@@ -95,11 +95,11 @@ def options(opt):
         default=False,
         help='Force enable standard JACK (jackd) even if D-Bus JACK (jackdbus) is enabled too',
     )
-    opt.add_option('--dbus', action='store_true', default=False, help='Enable D-Bus JACK (jackdbus)')
+    opt.add_option('--dbus', action='store_true', default=True, help='Enable D-Bus JACK (jackdbus)')
     opt.add_option(
         '--autostart',
         type='string',
-        default='default',
+        default='dbus',
         help='Autostart method. Possible values: "default", "classic", "dbus", "none"',
     )
     opt.add_option('--profile', action='store_true', default=False, help='Build with engine profiling')