Remove JBoss Maven repository specification from POM

Our parent POM should not have the JBoss Maven repository defined within it, as it makes it impossible to promote to Maven central as is. The primary reason we've done this is to simplify the process of setting up a development environment by modifying/customizing a ~/.m2/settings.xml file. However, we can take steps to make that significantly easier.

If we add a settings.xml file to the top-level of our codebase, developers don't even have to have a local ~/.m2/settings.xml file. Instead, they can build using:

$ mvn -s settings.xml ...

This settings.xml file should contain the JBoss Maven repository specification and any other custom settings (but no user names). It also provides examples for if they do want to modify their ~/.m2/settings.xml file.

We'd need to up the wiki pages to document the change, and also post the changes to the forum so that existing developers are made aware of the change.