Re: bundlelisation of the backend

[Nicola Pero]

I vote for removing the backend part of the library combo.

I know that would mean that if you compile your backend as a library, and
link against it, then you can use only a single backend at a time.

If you want to use more than one backend, you have to build backends as
bundles and load them dynamically.  Building backends as bundles should be
the default anyway.  I don't really see why people would want to build
them as libraries - except if bundles are not working on that platform -
in which case fixing bundles is something to be done before playing with
multiple backends anyway ...

I don't see major problems with compatibility ... The library combo is
accessed everywhere as a whole string, except inside the gnustep-make
package ...  So removing the last part shouldn't make any difference once
we update the internal part of gnustep-make and the gnustep-gui and
gnustep-xgps, gnustep-xdps makefiles ...  Or am I overlooking something ?

I'd like if we made the LIBRARY_COMBO stuff simpler and smarter (not that
I have a clear idea of how to do) without removing functionality.  Making
the backend a bundle and removing the last library combo part seems a good
start.