iOS: fix definition id overflow bug
#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
#815 upload events when PacoClient finished setting up
#816 add a log for duplicate notification dates
#816 1. create a method lastESMScheduleDate, and use it to calculate the next esm cycle start correctly;
2. don’t save the esm schedule array if it’s empty, so that we can always have a valid last generated esm schedule date to calculate next esm cycle start whenever the major task is executed.
#826 change the timeout of submitting events from 20 seconds to 25 seconds.
iOS: UIBackgroundFetchResultNoData seems to trigger the background fetch work too often than expected, just use UIBackgroundFetchResultNewData if there aren’t any pending events to upload or the uploading just failed.
iOS: add some logs
iOS: improve logs
#827 1. update UI only when running experiments are loaded    2. create properties for message label and button so that we can avoid adding duplicate label and button, and also update their visibility correctly
iOS: change the app id to just iOS for event payload, since we only need this to tell the difference among web, android and iOS
iOS: increase the version number by 0.0.1, since we've fixed a lot of things after the 1.1.0 beta test
#819 add another MKMapViewDelegate method to receive location updates, don’t update the conditionals for the map yet, log map update error information
Merge pull request #835 from google/ios-release-1.1.0

Ios release 1.1.0