[Bluetooth] stopDiscovery API fix to be compliant with TCT tests

stopDiscovery API is supposed to cancel an active discovery session.
If user cancels the discovery while there is no active discovery,
we should NOT return an error to pass TCT tests.
[Alarm] Initialize the "period" to null if its value is not set.
This can ensure the "period" be enumerable.
BUG=XWALK-2079
Merge pull request #350 from yejingfu/alarm-fix

[Alarm] Initialize the "period" to null if its value is not set.
Merge pull request #349 from eurogiciel-oss/stopDiscovery_noerror

[Bluetooth] stopDiscovery API fix to be compliant with TCT tests
Bump version to 0.80
Implementation of Tizen SSO APIs
Merge pull request #335 from izaman/master

Implementation of Tizen SSO APIs
Add initial support for MediaRenderer API.
BUG=XWALK-1195