Partial fix for vendor-cc-versus-gcc incompatibility on HPUX:

prefer aCC as c++ compiler if hpux_cc is selected as template.
Doesn't solve the problem if you have g++ and not aCC, however...

src/template/hpux_cc

@@ -9,3 +9,5 @@ DLSUFFIX:.sl
 YFLAGS:-d
 YACC:
 CC:cc
+# Make aCC be first C++ compiler name tried...
+CCC:aCC