Convert cglib to be a maven project

Initial basis to convert cglib to be a maven project, I suspect there would be further work needed to ensure this work correctly but hopefully helps.

- Two tests were disabled for now since they relied on a signed jar file.
- Maven needs to be updated to generate sources/javadoc jar files
I've added the sections for `<scm>`, `<issueManagement>`, `<ciManagement>`, and `<distributionManagement>`.

I'll look at `maven-license-plugin` and also `maven-remote-resources-plugin` to see about embedding the license.