Merge branch 'master' into dev

Conflicts:
	liblttng-ust/ltt-events.c
	liblttng-ust/lttng-context-vtid.c
	liblttng-ust/lttng-ust-comm.c
	libringbuffer/ring_buffer_frontend.c

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --cc include/lttng/ust-events.h
Simple merge

diff --cc liblttng-ust/ltt-events.c
Simple merge