Initial port of the state system to the LTTng 2.0 trace format

Rework the internal data structure (remove Tracefile.c, add a TraceState inside a Trace)
There is no callback by event id anymore, so all state event handler receive all the events.
Several files were reorganize (including moving them out of ltt to the lttv lib directly.

The current implementation use a temporary State structure, so it can only support on trace.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>