Break all the applications part of odl-openflowplugin-app-topology feature to their own feature, so that user can load the required module only.

Currently odl-openflowplugin-app-topology, bundles following 3 apps
(1) lldp-speaker
(2) topology-lldp-discovery
(3) topology-manager

This patch adds 3 new features that bundles these apps in their own features

(1) lldp-speaker -> odl-openflowplugin-app-lldp-speaker
(2) topology-lldp-discovery -> odl-openflowplugin-app-topology-lldp-discovery
(3) topology-manager ->odl-openflowplugin-app-topology-manager

old-openflowplugin-app-topology feature will be retained for backward compatibility.

In general projects installs the odl-openflowplugin-flow-service-rest feature that loads up the following bundles

(1) odl-openflowplugin-southbound
(2) odl-openflowplugin-app-config-pusher
(3) odl-openflowplugin-app-topology
(4) odl-openflowplugin-app-forwardingrules-manager
(5) odl-openflowplugin-app-reconciliation-framework

Apart from odl-openflowplugin-app-topology, rest all features bundle only single application. So now if user want to install specific bundle from odl-openfowplugin-app-topology, then user will have to install all these feature separately as there won't be aggregated features that provides different variant to user and having those variant can explode the number of features as well.

For example, if user don't want to use lldp based discovery, but they need topology service
, they need to install following features explictly:

(1) odl-openflowplugin-southbound
(2) odl-openflowplugin-app-config-pusher
(3) odl-openflowplugin-app-topology-manager
(4) odl-openflowplugin-app-forwardingrules-manager
(5) odl-openflowplugin-app-reconciliation-framework