py-matplotlib: make the gui and ipython support optional
py-matplotlib: make the gui and ipython support optional

ipython, nice as it is, is not required to use matplotlib. The UI bits
are also optional and dragging in Qt and Tcl/Tk for the library
shouldn't be the default.

EmreAtes/spack,krafczyk/spack,lgarren/spack,tmerrick1/spack,EmreAtes/spack,tmerrick1/spack,matthiasdiener/spack,lgarren/spack,EmreAtes/spack,tmerrick1/spack,skosukhin/spack,TheTimmy/spack,skosukhin/spack,LLNL/spack,mfherbst/spack,LLNL/spack,TheTimmy/spack,EmreAtes/spack,krafczyk/spack,skosukhin/spack,krafczyk/spack,matthiasdiener/spack,mfherbst/spack,iulian787/spack,tmerrick1/spack,LLNL/spack,krafczyk/spack,krafczyk/spack,matthiasdiener/spack,mfherbst/spack,lgarren/spack,EmreAtes/spack,tmerrick1/spack,skosukhin/spack,skosukhin/spack,lgarren/spack,mfherbst/spack,LLNL/spack,LLNL/spack,matthiasdiener/spack,TheTimmy/spack,TheTimmy/spack,iulian787/spack,lgarren/spack,matthiasdiener/spack,mfherbst/spack,TheTimmy/spack,iulian787/spack,iulian787/spack,iulian787/spack