Investigate adding an option fourth digit to InstallableComponents' versions

The use case is limited and the implementation has to do with “what happens if we need to ship a second version of a plugin that carries the major version of a third party project” (IOW jetty).

Goals and non goals

• If we cannot do this entirely within the interfaces, support code and base classes of “shib-profile” its too complicated

• The properties file has to be backwards compatible with 5.* and 4.*

• Non goal: The windows trick whereby the 4th digit doesn’t have an order, but allows overinstall. (so if you ask to install 1.2.3.0 on 1.2.4.0 it will fail but on 1.2.3.1 it will work