[CORE] Allow Fragment Bundles

[nickgaray]

Currently all bundles are being registered and started. We need to allow fragment bundles to be registered but this type of bundle does not require activation as it contributes functionality to a host bundle

This is an example of an osgi closure in a module that contributes custom forms to sensorhub-web-ui-core

osgi {
    manifest {
        attributes('Bundle-Vendor': 'Botts Innovative Research, Inc.')
        attributes('Bundle-SymbolicName': 'com.botts.ui.datafeed')
        attributes('Bundle-Version': version)

        // THIS is the important part:
        attributes('Fragment-Host': 'org.sensorhub.sensorhub-webui-core')

        attributes('-dsannotations': 'false')
        attributes('Export-Package': '')
        attributes('Import-Package': '*;resolution:=optional')
    }
}

In order to satisfy this SensorHubOSGi needs to skip attempting to start bundles that have the Fragment-Host attribute