stex Version 1.2.1

- recast include files preplib.ss, dsm.ss, and script.ss as libraries,

  replaced global variables with parameters (those that cross library
  boundares out of necessity, and those that don't for consistency), and
  Makefile uses whole-program compilation to create a single object file
  for each program.  (note: this last requires an update to Chez Scheme's
  compile-whole-program to transfer the hash-bang line from the wpo file
  to the object file.  this update should be pushed shortly.)
    dsm.ss, preplib.ss, script.ss, scheme-prep.ss, html-prep.ss,
    fixbibtex.ss, Makefile
- Makefile provides a PREFIX variable that can be overridden to change
  in one shot the tree under which the Scheme executable is installed and
  under which the stex library should be installed.
    Makefile
- Mf-stex now assumes Scheme and STEXLIB variables have been set by the
  including make file, and Makefile.template does so, and also includes
  Mf-stex via the directory identified by STEXLIB.  Mf-stex looks for
  and runs the binary scheme-prep, html-prep, and fixbibtex if they
  exist for the machine type of the specified Scheme in the specified
  STEXLIB.  Otherwise it uses the source scheme-prep.ss, html-prep.ss,
  and fixbibtex.ss, setting libdirs appropriately.
    Mf-stex, Makefile.template
- added .gitignore to ignore editor temp files
    .gitignore