#815 add some logs
#815 set ENABLE_NS_ASSERTIONS to NO for release
#815 add method to return the loading status of running experiments and notifications
#815 make sure the major task isn’t executed more than once at the same time
#815 stop executing major task is PacoClient didn’t finish loading running experiments and notifications
#815 add synchronized atomic protections to notification manager and event manager
Merge pull request #823 from google/issue815

#815