Test backend implementation for kab2.

A GDBM database is perhaps the easiest backend to write, and is actually quite
useful for our purposes. GDBM is a tiny library, yet it's small and fast
and supports enough features to make this implementation servicable yet easy
to understand.

There are only five methods that a backend implementation has to implement:

bool init   (const KURL &);
bool read   (const QCString &, QByteArray &);
bool write  (const QCString &, const QByteArray &);
bool remove (const QCString &);

QStrList allKeys();

As you can see, it's incredibly easy to map these methods to GDBM methods. If
you don't see that, read the GDBM man page. It's really extremely simple.

Questions, comments etc. should be directed to Rik <rik@kde.org>

