Adding --with-debug option

configure.ac

@@ -73,6 +73,7 @@ AC_SUBST(PKGADD_VENDOR)
 
 dnl Check for programs
 AC_PROG_CC
+SFL_CXX_WITH_DEBUG
 AC_PROG_CXX
 AC_PROG_CPP
 AC_PROG_INSTALL

m4/sfl-internal.m4

+AC_DEFUN([SFL_CXX_WITH_DEBUG],[
+
+	AC_ARG_WITH(debug,
+		AS_HELP_STRING(
+			[--with-debug],
+			[Set 'full' to enable debugging information @<:@default=no@:>@]
+		),
+		[with_debug=${withval}],
+		[with_debug=no]
+	)
+	if test "x$with_debug" = "xfull" -o "x$with_debug" = "xyes"; then
+		CXXFLAGS="$CXXFLAGS -g"
+		CPPFLAGS="$CPPFLAGS -DDEBUG"
+	fi
+])