Log Message:
Update Chicken to 4.2.0.

Changes in 4.2.0:

- added compiler option `-emit-all-import-libraries'
- added `reexport'
- added compiler and interpreter option `-setup-mode'
- various minor performance improvements
- fix for 'create-directory' when parents wanted
- `for-each-line' and `for-each-argv-line' have been deprecated
- chicken-install tries alternative servers if server responds with error
- fixed load bug (ticket #72)
- new library procedure `get-condition-property'
- many mingw build fixes (thanks tp Fadi Moukayed)
- setup-api: deprecated `cross-chicken' (use `cond-expand' or
  `feature?' instead)
- added topological-sort to data-structures unit; chicken-install
  sorts dependencies before installing them
- "-optimize-level 2" enables inlining by default
- disable executable stack in assembly code modules (patch by
  Zbigniew, reported by Marijn Schouten)
- csc now always exits with a status code of 1 on errors (patch by Zbigniew)