bugfix for RC7
return string for status
throw correct error ID in systeminfo
[Bug fixs] TDIS-6116, TDIS-6117, trigger one time of sensor event when application call add event listener.
Merge pull request #240 from jacobchen/next

[Bug fixs] TDIS-6116, TDIS-6117, trigger one time of sensor event when a...
[Calendar] fix bug: failed to find canlendar

* If there is no calendar items exist, we shouldn't let engine to
  extract any more
Merge pull request #241 from xuzhang/dev

[Calendar] fix bug: fail to find filter
[bug fix] TDIS-5641 return correct WebAPIException
[bug fix] TDIS-5394, 5393 added argument type checking.
lint
[bug fix] TDIS-5851, 5853 - type checking enhancement in callhistory
[Bug fixs] TDIS-6514, TDIS-5621, Handled the option argument situation. Added state item to SIM settings.
[bug fixs] TDIS-5980 The CalendarAttendee interface could not work well
[Application] fix bug TDIS-6431.
[Contact] Bug fixing.
Add read only attribute for constructor.

* [NABI-RSA] TDIS-5819
Merge pull request #247 from wcwang/next

[Contact] Bug fixing.
[bug fix] TDIS-5520 add type checking in MessagingService
Merge pull request #246 from xuzhang/dev

[Application] fix bug TDIS-6431.
[bug fixes] TDIS-5714 Neither successCallback function nor errorCallback function could be invoked
Merge pull request #243 from zhizhangchen/fix-TDIS-5980

[bug fixs] TDIS-5980 The CalendarAttendee interface could not work well