Log Message:
Update to 20091218, provided by J.A.Neitzel in PR 42536. Set LICENSE.

Changes:
1) This update fixes a compilation problem on AIX caused by not
wrapping WCOREDUMP(s) with #ifdef WCOREDUMP ... #endif.

2) General code cleanup and rechecking w/ splint(1) reduces
unnecessary code duplication and eases future maintenance.

3) This update adds the program name to osh diagnostics (e.g.,
"osh: syntax error") for the sake of user friendliness.