Finally figured out that HP's cpp won't do ANSI preprocessing constructs

unless you feed it -Aa or -Ae switch.  Autoconf does not know about this,
but we can fix it in the hpux_cc template file.  I knew templates were
good for something ;-)

src/template/hpux_cc

@@ -8,5 +8,6 @@ DLSUFFIX:.sl
 YFLAGS:-d
 YACC:
 CC:cc
+CPP:cc -E -Ae
 # Make aCC be first C++ compiler name tried...
 CCC:aCC