When a feature is generated from a bundle project, include that bundle in the feature

We're migrating a custom plugin framework over to Karaf and would like to both create the OSGi bundle and generate the associated Karaf feature in the same Maven project. Otherwise downstream clients will need to create two Maven projects for each plugin: one to create the bundle, and one to create the Karaf feature.

The proposed change is to consider the project packaging, and if it is "bundle" then include the main project artifact (ie. the bundle itself) in the generated feature. This requires no configuration change and should not affect anyone generating features in isolation. We could also add a new flag such as "includeProjectArtifact" so this change has to be explicitly enabled, if people prefer.