Move def of CYGWIN_HEADERS to s files
-------------------- ChangeLog entries follow: --------------------
src/ChangeLog addition:
2010-01-14 Ben Wing <ben@xemacs.org>
* syswindows.h: Don't define CYGWIN_HEADERS here.
2010-01-14 Ben Wing <ben@xemacs.org>
* s/cygwin32.h:
* s/mingw32.h:
Define here instead so it's available in all files. Fixes
compile problems in database.c in some cases.