Add -no-c++11 to Mac configure options

Without this we can not deploy to 10.6.
The libraries in the binary installer with this change
are compiled without c++11 support so there is no
dependency to libstdc++ which is available only
on 10.7 onwards.

See:

http://qt-project.org/wiki/Qt510RC1KnownIssues
http://lists.qt-project.org/pipermail/development/2013-June/011293.html

Change-Id: Ic4a76d99d62fcbada1b33815a18231b9e500a3d0
Reviewed-by: Kai Koehne <kai.koehne@digia.com>