Parse and forward instument probes

Report error if userspace probes created with wildcard events.

Conflicts:
	src/bin/lttng/commands/enable_events.c
Add usage for userspace instrumented probes

Conflicts:
	src/bin/lttng/commands/enable_events.c
Handle enable_event command with instrument target

Define a structure holds the event instrument target data. The last
data item is a flexible array that contains a variable number
of target path.

Add instrument target data to the prototype of cmd_enable_event(),
and process the instrument target data form clients in the function.

Add error codes of processing instrument traget data.

Conflicts:
	include/lttng/lttng-error.h
	src/bin/lttng-sessiond/main.c
Handle instrument target in cmd_enable_event()

Add instrument target data to the prototype of event_ust_enable_tracepoint().
Handle instrument target in event_ust_enable_tracepoint()

Add instrument target data to the prototype of trace_ust_create_event()
and trace_ust_find_event().

Update the test_ust_data unit test with the new prototype.
Handle instrument target in trace_ust_create_event()

Copy instrument target and probe information from client.

Free allocated instrument target data when destroying events.

Also remove unused LTTNG_EVENT_FUNCTION_ENTRY event type.

Conflicts:
	src/bin/lttng-sessiond/trace-ust.c
Handle instrument target in trace_ust_find_event()

Add instrument target as a ltt_ust_ht_key and handle it in function
trace_ust_ht_match_event() and add_unique_ust_event().
Add 'dynamic-inst-release' to travis-ci
Add unit test for enabling events with instrument target
Copy instrument target data in shadow_copy_event()

Add instrument target data to ust_app_event struct.

In delete_ust_app_event(), free the copied instrument target data,
and also remove a redundant NULL check.
Add instrument target data to find_ust_app_event()

Add instrument target data to the prototype of find_ust_app_event()
and wherever it is called.

In ht_match_ust_app_event(), use instrument target as one of the
matching criteria.

Add instrument target as a key in add_unique_ust_app_event().