[gnote] Add configure option for C++11

[Aurimas Černius <aurimasc src gnome org>]

commit 04ece28bd69062a233f12b8846f51fb62eef2c10
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Sun Apr 27 21:28:35 2014 +0300

    Add configure option for C++11

 configure.ac |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 07445be..1753cbd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -62,7 +62,13 @@ LT_INIT([disable-static])
 
 AC_LANG_CPLUSPLUS
 AC_LANG_COMPILER_REQUIRE
-AX_CXX_COMPILE_STDCXX_11([], [optional])
+
+AC_ARG_WITH(cxx11_support, [  --with-cxx11-support    Compile with C++11 support, if 
available.],[cxx11_required="${withval}"],[cxx11_required="optional"])
+case "$cxx11_required" in
+  yes) AX_CXX_COMPILE_STDCXX_11([], [mandatory]) ;;
+  optional) AX_CXX_COMPILE_STDCXX_11([], [optional]) ;;
+esac
+
 AC_CHECK_PROG(HAVE_DESKTOP_FILE_VALIDATE, [desktop-file-validate], [yes], [no])
 if test $HAVE_DESKTOP_FILE_VALIDATE == "no"; then
   AC_MSG_ERROR([desktop-file-validate not found])