Also communicate partition descriptions in PIO write interface.

doc/tex/c_quick_ref.tex

doc/tex/f_quick_ref.tex

examples/pio/collectData.c

examples/pio/collectDataNStreams.c

examples/pio/compareResourcesArray.c

src/cdi.h

src/cdi.inc

src/cdiFortran.c

src/pio_interface.c

src/pio_interface.h

src/pio_rpc.h

src/pio_server.c

src/stream.c

tests/pio_write.c