Use modified Debian packages -- management issues

[Kai Grossjohann <kai.grossjohann@gmx.net>]

I would like to compile Tora with Oracle support.  If I want to do it
once, I do like this: I fetch the sources with apt-get, then I edit
debian/rules (perhaps other debian/* files, too), then I build the
package, then dpkg -i.

But when a new version of the Debian package comes out, I have to
repeat the whole process.  This quickly becomes boring.  I'm sure
there is a way to automate this.  But how?

Also, I would like to make the modified package available to others.
I already have a directory to upload to, and my colleagues have the
right line in sources.list.  However, when a new Debian version comes
out, they might do a dist-upgrade, and then they will lose the Oracle
functionality.  How to avoid this?

Kai