 -- IO functions directory --

 * This is the directory containing input/output functions.

 * Files:
   - io_binary.py: Contains the functions to write output in binary format.
   - io_pdb.py: Contains the functions to read pdb structure files and to 
      create pdb trajectory output files.
   - io_xml.py: Contains the functions used to read the xml input file and
      to format the restart output file.
   - io_xyz.py: Contains the functions to read xyz structure files and to 
      create xyz trajectory output files.
