sink-input: Log format negotiation better

This provides more details on format negotiation success and failure to
make debugging problems easier.
pstream: Fixup hangs caused by recent iochannel patch

Now that we don't *always* get a callback after having written
something, make sure we can continue writing as long as it fully
succeeds.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
mainloop: Document need for mainloop lock around pa_mainloop_api_once

This needs us to expose a bit of implementation detail, but this seems
to be the cleanest way without an API change.

The specific problem is that pa_mainloop_api_once() needs to first
create a defer event and then set its destroy callback. If the defer
event is completed before the callback is set, an assert will be
trigerred.
zeroconf: Fix pa_mainloop_api_once usage

We need the mainloop lock to be taken around pa_mainloop_api_once() to
prevent an assert due to the defer event creation and setting of the
destroy callback not being performed atomically.
combine: Fix crash in output freeing

The outputs are removed from the idxset before output_free() is
called. Trying to remove them again in output_free(), and asserting
that it should succeed caused crashing whenever outputs were freed.

This bug was introduced in commit
061878b5a47ed9aa05d12430b039874b63c29a84.

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=65901
bluetooth: Fix too late assertion

u was dereferenced before the assertion that checks that u isn't NULL.
cli, log: Improve the set-log-target functionality

Add a new log target 'newfile:PATH', and refactoring 'pa_log_target_type'.

Signed-off-by: Shuai Fan <shuai900217@126.com>
log: Fix error message

file_path contains the last tried file name, including the suffix, so
the error message was wrong:

    Tried to open target file '/tmp/test.log.99', '/tmp/test.log.99.1',
    '/tmp/test.log.99.2' ... '/tmp/test.log.99.99', but all failed.