Log Message:
Update to Chicken 4.8.0.5
Requested by Peter Bex.

4.8.0.5

- Security fixes
  - CVE-2013-4385: read-string! no longer reads beyond its buffer when
    length is #f.
  - poll() is also used on cygwin by enabling the fix for CVE-2012-6122
  - file-creation-mode now passes a valid value to umask when its argument
    is omitted.  (Also ensure it always returns the old umask value.)
  - Fix a data corruption problem in list->queue.

- Core libraries
  - read-string! behaves correctly in presence of EOF.
  - Several subtle problems in the reader in the presence of EOF are fixed.
  - Use poll() instead of select() on cygwin.

- Runtime
  - Fix an issue on initial seed of the random number generator.

4.8.0.4

- Runtime
  - Ensure correct type is used for sigsetjmp(3) buffer.  This fixes,
    for example, a bus error in 32-bit OS X builds (#1021).

- Core libraries
  - Export file-type from the posix unit.

- Build system
  - Use inexact comparison for flonum tests, as there is sometimes a
    miniscule difference between trig functions computed by libc and
    those precalculated by gcc.