make outfile name optional
add logs to git ignore
Output filename is based on input filename

Unless specified otherwise.
Correct use of exists
Batch mode now works. Updated readme text.
Remove do_chomp_batch (no longer used)
Remove batch arg_parser reference.
Merge branch 'feature-oommfdecoder' into develop
Merge branch 'develop' of https://github.com/deparkes/OOMMFTools into develop