Changes from 1.5beta0 ----------------------------------------

- INTERFACE NEW (lut.c, rmap.c, imap.c): added -min and -max flags
to allow specifying the used input range
- INTERFACE NEW (unrrdu.h flotsam.c, save.c): now allow specifying
flags for gzip and bzip2 compression
- INTERFACE NEW (heq.c): added -a flag for new "amount" argument to
nrrdHistoEq()
- convert.c, quantize.c, resample.c: more usage info

Changes from 1.4 ------------------------------------------

private.h:
- changed SAVE macro to take file name as first arg, this 
change affected all *.c files.

unu.c, Makefile:
- removed "(unrrdu)" from main unu banner
- added imap.c and with that, "unu imap", for applying
irregular maps

gamma.c, histo.c, jhisto.c, quantize.c:
- nrrdMinMaxClever() renamed to nrrdMinMaxCleverSet()

heq.c:
- added "-m" flag to allow learning of the regular map
used to achieve histogram equalization

lut.c, rmap.c, imap.c:
- added "-t" flag to specify output type (previously always
used map type), and in lut and rmap, added proper handling
of the "-r" rescaling flag.

lut.c:
- INTERFACE CHANGE: "-l" flag changed to "-m", in order to
agree with flag for unu rmap and unu imap.
- change to nrrdApply1DLut() call: added "rescale" argument.

make.c:
- added "-c" flag to allow setting the content
- added "-h" flag to allow generation of detached header
files; this turned out to be rather annoying.

rmap.c:
- change to nrrdApply1DRegMap() call: added "rescale" argument.