Not working commit; missing NativeStorageClient or workaround...
Rough draft sketch of introducerless client
Teach client to talk to storage nodes in tahoe.cfg
add minimal /introducerless_config page
remove seed and furl columns from server list
remove use_introducer option, update docs
fix introducerless storage servers

it turns out the _publish method registers with the tub too, not just the
introducer
Merge branch 'introducerless' into truckee68

Conflicts:
	docs/configuration.rst
	src/allmydata/client.py
	src/allmydata/web/root.py
update NEWS.rst about introducerless operation
add web.reveal_storage_furls option
Merge branch 'introducerless' into truckee68
add get_config to FakeClient to make test_web pass
Merge branch 'introducerless' into truckee68