Improving HiveMind naming conventions

Because I'm working to make HiveMind feel a bit more like Eclispe plugins, I'm beginning to rename things to be more consistent.

• <configuration> --> <extension-point>
• <contribute-configuration> --> <extension>
• <contribute-service> --> <extend-service>

In addition, I'm scrapping "internal contributions" to extension-points. Instead, we'll allow <extension> to use an unqualified name for an extension point that's within the same module.