To compile archtoi

1. Get the latest release, preferably a tagged release
2. You need the cfitsio library. Set the CFITSIODIR environment variable
   to the location of the library (the directory should contain fitsio.h
   and a subdirectory $(HOSTTYPE) (GNU make standard macro) should
   contain libcfitsio.a)
3. run the 'mkd' script
4. run make

if you want to build a statically-linked version, run
make NOSHLIB=Y