I now commited the changes to mlogger (mlogger.c, msystem.h) implementing data
compression using zlib (svn revision 3845)

To enable compression, observe that mlogger is compiled with -DHAVE_ZLIB (see
the Makefile), in "/Logger/Channels/NNN/Settings", set "compression" to "1" and
the filename to "run%05d.mid.gz" (note the suffix ".gz").

In the Makefile, I only enabled HAVE_ZLIB for Linux, as that is the only
platform I tested. If somebody can test compression on Windows, please do and
let us know.

My ROOT analyzer (rootana) package can read compressed MIDAS files directly and
if one wants to add this capability to other MIDAS-related packages, one is
welcome to use my TMidasFile.cxx as an example
(http://ladd00.triumf.ca/viewcvs/rootana/trunk/TMidasFile.cxx?view=markup).

K.O.