Split out kupfer plugins to a separate repository

[Ulrik Sverdrup <ulrik sverdrup gmail com>]

Hi,

I think we should consider the possibility of separating core kupfer
from the growing mass of plugins.

Core kupfer would take most of the now-default plugins and not so much
more, and many of the large other plugins go into a community package.

Technically, it would be separate git repositories and separate
tarballs, and separate localization work. Localization will be
relatively easy since we still have all the "community" plugins
collected in one place.

For the developers it could mean that we make a maintenence team for
the community plugins package, which should make it easier for more
people to work on the plugins. I can continue to maintain the core
kupfer, as well as being part of community maintenence team (if
wanted).

For some users, they have to install two tarballs or two distribution
packages instead of one, but if you use a package from a repository it
is not going to be a big difference. The users that only want some
basic functionality can have that if they skip installing community
plugins.

What do you think?

Ulrik