add sync_test.c and revised Makefile

2014.8.4
0804
Merge remote-tracking branch 'origin/master'

Conflicts:
	.gitignore
sync_test
Merge remote-tracking branch 'origin/master'
Merge branch 'command' of http://github.com/oc224/BB

Conflicts:
	Makefile
try
initMerge remote-tracking branch 'origin/signal' into signal