Elle Microstructural Modelling SVN Code

gbdiff.elle.cc: Changed it to ignore Timestep if user specifies number
of stages. User beware - no checks in this case.

polygon.cc: error in RegionExpanding initialisation

code for win batch file output. Added exchange process

flynns were inverted

allow user data to control unode output

problem reassigning unodes, showed up on Win32

don't include ppm.h

elle2poly does topology test after reading tmp.elle.
Need to rewrite tmp.elle in case topology has changed,
else basil2elle will be confused

add read image fn

image read fn declaration