add a glossary to the spec

[Ladicek]

The specification often refers to terms it doesn't define. There are 2 categories of such terms:

1. Terms defined by other specifications, such as JLS or Jakarta Interceptors.
2. Terms "invented" for the CDI specification, but not properly defined anywhere.

For the first point, good examples are "supeclass" (or "superclass type", although that is not exactly defined in the JLS to be precise, although the JLS uses the term on several occasions).

For the second, a good example is "actual type".

I believe we should add a chapter called Glossary that would contain a list of these terms and for each of them, either a link to the specification it is defined in (1st case), or a definition (2nd case).