Tmf: Trace synchronization using network events

Tmf: Trace synchronization using network events

* Event matching infrastructure allow to create dependencies between 2 events.
* Network events (TCP packets) are matched for LTTng 2.0 traces, using one of
  two techniques: fgiraldeau's dynamic probe addon module, or an experimental
  branch with additional data on net_* tracepoints of lttng-modules.
* Traces in an experiment are synchronized using the Fully Incremental Convex
  Hull algorithm.
* A trace's timestamps can be modified using Timestamp Transforms classes.
  TmfTimestampTransformLinear takes a slope and/or an offset.
* Once synchronized, the trace is copied, without its supplementary files
  so the state system is regenerated with synchronized time.
* A new synchronization view shows statistics about the synchronization.
* The synchronization information is kept at the experiment level to be able
  to view synchronization's statistics after first sync.
* Synchronization formula for a trace is saved in supplementary files.
* Unit tests for trace synchronization.

Change-Id: I1971fcd856254fc5654c609d6146904cd3dfd25c
Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Reviewed-on: https://git.eclipse.org/r/14056
Tested-by: Hudson CI
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
IP-Clean: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>