Improved CFLAGS/CPPFLAGS handling

- Language extensions, such as _GNU_SOURCE are now enabled through
  CPPFLAGS by the configure script, rather than within the source code.
- Moved some configure-time CFLAGS to CPPFLAGS, where appropriate.
- Fixes bugreport:8211, thanks to Neoth
  http://hercules.ws/board/tracker/issue-8211-compiling-warning-in-linux

Signed-off-by: Haru <haru@dotalux.com>

3rdparty/libconfig/Makefile.in

@@ -1,6 +1,8 @@
 # Copyright (c) Hercules Dev Team, licensed under GNU GPL.
 # See the LICENSE file
 
+# @configure_input@
+
 LIBCONFIG_OBJ = libconfig.o grammar.o scanctx.o scanner.o strbuf.o
 LIBCONFIG_H = libconfig.h grammar.h parsectx.h scanctx.h scanner.h strbuf.h wincompat.h
 

3rdparty/mt19937ar/Makefile.in

@@ -1,6 +1,8 @@
 # Copyright (c) Hercules Dev Team, licensed under GNU GPL.
 # See the LICENSE file
 
+# @configure_input@
+
 MT19937AR_OBJ = mt19937ar.o
 MT19937AR_H = mt19937ar.h
 

Makefile.in

@@ -1,6 +1,8 @@
 # Copyright (c) Hercules Dev Team, licensed under GNU GPL.
 # See the LICENSE file
 
+# @configure_input@
+
 @SET_MAKE@
 
 HAVE_MYSQL=@HAVE_MYSQL@
@@ -145,7 +147,7 @@ distclean: clean
 	@-rm -f $(MF_TARGETS) config.status config.log
 
 sysinfo:
-	@./sysinfogen.sh src/common/sysinfo_new.inc @CFLAGS@
+	@./sysinfogen.sh src/common/sysinfo_new.inc @CFLAGS@ @CPPFLAGS@
 	@if cmp -s src/common/sysinfo.inc src/common/sysinfo_new.inc; then \
 		rm src/common/sysinfo_new.inc ; \
 	else \