* Don't set File.etx when reading .cnf files. strings are null-terminated
  in *.cnf files.
* Don't open files shareable - they are not. This could explain .cnf file
  corruption when using this library.
* read() and write():
- If passed just the .cnf filename, get the full path automatically
  If not passed a 'struct' argument, figure it out from the filename
* Make the CNF object the last statement so that this library may be loaded
  into its own scope using: var cnflib = load({}, 'cnflib.js');