Refactored discovery API

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
Added UpnpDiscoveryService and a HueBridge discovery participant

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
implemented tracker behaviour for listeners

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
Changed behavior of abortScan in AbstractDiscoveryService and fixed getThingTypeUID in ThingUID.
Adapted discovery tests according to new API.

Signed-off-by: Dennis Nobel <d.nobel@external.telekom.de>
Added new methods startScan(bindingId), stopScan(bindingId), supportsDiscovery(bindingId) and supportsDiscovery(thingType) to DiscoveryServiceRegistry.
Added support for multiple discovery services for the same type.
Fixed not stopping scheduler, when start fails in AbstractDiscoveryService.
Adapted tests.

Signed-off-by: Dennis Nobel <d.nobel@external.telekom.de>
added discovery services for Hue binding

Signed-off-by: Kai Kreuzer <kai@openhab.org>
added unit tests for hue discovery

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
Merge commit '6fd3db9e33dd148eec089bd47bab523d5d750400' into discoverywithhue

Conflicts:
	targetplatform/SmartHome Runtime.launch

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
changed method call to OSGi r4.2 compliance

Signed-off-by: Kai Kreuzer <k.kreuzer@telekom.de>
Merge pull request #60 from qivicon/discoverywithhue

Refactored discovery service API and added discovery for hue binding