The background update is never guaranteed to complete before the cache
is used, so don't bother trying it at the beginning.  Instead, put a
timeout on a foreground update.

If the foreground update fails:

* If there's no available cache file then die.

* If there is a previous cache file then use it and log a warning.

* Do a background update at the end of the monitor event.

Also remove commas in the "smb ports" list before use, since (newer?)
testparm seem to insert commas into the default value.  Update the
associated test to add a comma.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Pair-programmed-with: Amitay Isaacs <amitay@gmail.com>

(This used to be ctdb commit 8c6f511254ecb0381a609b37e3a0ee6e5ec5d562)

It currently needs the real testparm command installed even though it
only uses limited features.  It is easy enough to fake up the
functionality that 50.samba uses.

Signed-off-by: Martin Schwenke <martin@meltin.net>

(This used to be ctdb commit 7ef9916bd95ff2472359a412eac5489f1aad2dce)

This sets up a more useful convention and avoids future .gitignore
problems.

Signed-off-by: Martin Schwenke <martin@meltin.net>

(This used to be ctdb commit 58c696dc600f1073e693930da061776b6fb199f2)