modify lpel flag
Support Source/Sink tasks + fix bugs
- Modify glue_snet.c to support source/sink tasks
- Fix small bug in collector.c (the sync rec should be sent only when
  the ready stream set is empty --> otherwise, it may forward unexpected
  sort end. This happens when there is initial branches mixed with
  non-initial ones.)
- Implement SNetStreamGetId for debugging (not support for pthread
  back-end)
- Modify mon_snet to obtain log files for source/sink and wrappers
- update LOGFORMAT
Fix small bug in collector.c
- this appeared while fixing GC bug
- the sync rec should be sent only when the ready stream set is empty --> otherwise, it may forward unexpected sort end. This happens when there is initial branches mixed with non-initial ones.
Fix bug in garbage collector + add SNetStreamGetId(for debugging)
 - Fix bug: "Received sort records do not match"
    This happens as the sort_end records do not pass the parallel entity
    but pass the collector entity (See the gc report for more detail)
    This is fixed by sending a special sort_end record to notify the
    paired collector when a parallel entity terminates itself.
Forgot to add the SNetStreamGetId declaration
Merge branch 'master' into centralQ
 - to fix the bug of garbage collector
add LPEL_FLAGS: for usage option flags in lpel
merge master:
  + fix monitoring bug when using T without S (task status is wrong)
Merge branch 'centralQ' of git://github.com/nguyenvuthiennga/snet-rts into centralQ

Conflicts:
	src/threading/lpel/lpelif/glue_snet.c