split A -> A + B

[PICCA Frederic-Emmanuel <frederic-emmanuel.picca@synchrotron-soleil.fr>]

Hello, 

I am working on a python package fabio, for the new verison I will add the python3 pacakge and a pacakge which will contain only the scripts.

so

beffor

python-fabio (with the scripts moved into fabio-viewer)
python-fabio-dbg
python-fabio-doc

after

fabio-viewer
python-fabio
python-fabio-dbg
python3-fabio
python3-fabio-dbg
python-fabio-doc

Now I would like to know how to write the Breaks and Replaces.
I tryed with this but I got an error with piuparts. 
For the upgrade I am also wondering if the python-fabio should not depends on fabio-viewer to propose the same functionnality thant the previous python-fabio pacakge.

Package: fabio-viewer
Architecture: all
Section: python
Depends: ${misc:Depends},
         ${python:Depends},
	 python-fabio (>= ${source:Version})
Breaks: python-fabio (<< 0.2.2+dfsg-2)
Replaces: python-fabio (<< 0.2.2+dfsg-2)


Package: python-fabio
Architecture: any
Section: python
Depends: ${misc:Depends},
         ${python:Depends},
         ${shlibs:Depends},
         pymca,
         python-six
Recommends: python-imaging,
            python-lxml,
            python-matplotlib
Suggests: pyfai,
          python-fabio-doc


 Selecting previously unselected package fabio-viewer.
  dpkg: regarding .../fabio-viewer_0.2.2+dfsg-2_all.deb containing fabio-viewer:
   fabio-viewer breaks python-fabio (<< 0.2.2+dfsg-2)
    python-fabio (version 0.2.2+dfsg-1) is present and installed.
  
  dpkg: error processing archive tmp/fabio-viewer_0.2.2+dfsg-2_all.deb (--install):
   installing fabio-viewer would break python-fabio, and
   deconfiguration is not permitted (--auto-deconfigure might help)

thanks for your help

Frederic