[AudioSystem][IVI] Fix crash while destroying audiosystem extension object.

Missing NULL check added to pulseaudio context object in AudioSystemInstance
destructor. This allows clean shutdown of audiosystem extension process.

BUG=XWALK-1964
Merge pull request #334 from avalluri/audiosystem

[AudioSystem][IVI] Fix crash while destroying audiosystem extension obje...
Bump version to 0.72
[Bluetooth] Implement API based on Tizen bluetooth framework

Make 3 bluetooth extension backends : bluez4, bluez5 and tizen_capi

- add bluetooth_instance_capi.* source code using Tizen bluetooth C API
- remove Tizen C API calls from bluez4 backend
- fix bluez5 backend build
- modify device class major, minor and services JSON messages

BUG=XWALK-1065

Signed-off-by: Corentin Lecouvey <corentin.lecouvey@open.eurogiciel.org>
Merge pull request #308 from eurogiciel-oss/bluetoothAPI

Implement bluetooth API based on Tizen bluetooth stack
Bump version to 0.73
Added initial vehicle API

BUG=XWALK-865
SPEC=https://rawgit.com/w3c/automotive-bg/master/vehicle_spec.html
Fix to make sure mediaserver properties are set to
the correct value.

    BUG=XWALK-2015
Merge pull request #337 from brianjjones/master

Fix to make sure mediaserver properties are set
Bump version to 0.74
[Content] Add listeners and events support

Add support for subscribing to media content change events
via setChangeListeners and unsetChangeListeners methods.

Also, some debug macro tunings.
Merge pull request #339 from poussa/events-and-more

[Content] Add listeners and events support
Fixed the resolution doesn't match LCD resolution when using
Systeminfo DISPLAY attribute.

BUG=XWALK-1927
Merge pull request #332 from tripzero/master

Initial vehicle API support
Bump version to 0.75
Merge pull request #338 from qjia7/master

Fixed the resolution doesn't match LCD resolution when using Systeminfo DISPLAY attribute.
[Filesystem] Fix and complete the API

Implement the spec.
Fix and pass the TCT tests.
Fix and complete the example.

BUG=XWALK-1071
BUG=XWALK-1827
Merge pull request #336 from eurogiciel-oss/XWALK-1827

[Filesystem] Fix and complete the API
[Bluetooth] Init tizen capi backend in BluetoothInstance

It was previously done at the extension creation step and
it prevented from performing TCT bluetooth tests.
Bump version to 0.76