Clean up the code in bin/ to reduce warnings from GCC3.

Clean up the code in bin/ to reduce warnings from GCC3.

Stage 3 of 5 or so: cleanups to cp, cpdup, and date.
- Add ``const'' to  appropriate variable declarations and casts.
- Convert ``quad'' types to ``long long''.
- Convert appropriate ``int'' types to ``size_t'' and ``dev_t''.
- Rename functions/variables to not conflict with globals.
- Add/remove function prototypes and #includes as appropriate.
- Split a long string constant.
- Convert K&R style declarations to ANSI style.

Submitted-by: Simon 'corecode' Schubert <corecode@fs.ei.tum.de>