Java Gnats database

[Tom Tromey]

I've merged the Java Gnats database into the gcc Gnats database.  The
Java Gnats database still exists, but it is read-only.  A warning to
that effect is displayed on the main page.

Expect to see a lot of email from the new PRs (over 300).  As far as I
could determine, this email is unavoidably generated by the PR filing
process.

Anyone with write access to the old Java Gnats database now has write
access to the gcc database with the same username and password.

The new database has only two Java-related categories: `java', for the
front end, and `libgcj', for the runtime.  In practice we discovered
that finer granularity than this wasn't really useful -- we ended up
using the `responsible' field more than the category.

Tom