Fix: recv creds comm should handle partial receive

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add -j/--jul to lttng UI and ABI

The JUL domain is set as unsupported in the session daemon so only the
client side is implemented.

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add jul.c/.h to sessiond code

The JUL domain is added to a ust session and created/destroyed in the
trace-ust.c API.

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add JUL registration thread

Listening on port 5345 by default and adds the --jul-tcp-port option to
the session daemon command line options.

At this commit, the thread is started and listening for incoming
registration but they are not handled.

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add jul-app ABI/API and handle registration

Registration is done in the jul thread and the created jul-app are
attached to existing UST app.

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] Enable a single JUL event working

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] Enable all JUL event command

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] disable a JUL event and all

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] add JUL update on registration support

Signed-off-by: David Goulet <dgoulet@efficios.com>
[HEAD MERGE] Add lttng list -j command to list possible events

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] add list JUL domain for a session

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] fix: list -j syntax in help

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] Fix disable all JUL event to handle wild card

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] Don't disable UST event for JUL and fix shit

Signed-off-by: David Goulet <dgoulet@efficios.com>
[MERGE] Fix: change default JUL channel

Signed-off-by: David Goulet <dgoulet@efficios.com>