Ansification plus some minor knf. No binary change on i386 and
sparc64, binary change in lex.o on macppc due to introduction of
dopprompt() prototype. ok millert@

Remove unused OS dependent #ifdef blocks, #defines and macro abstraction.
First step in making the ksh code easier to read. From Matthias Kilian

typos from Jared Yanovich;
ok deraadt@

Import pdksh 5.2.7.