shiboken: Bump to version 1.2.1, fix build issue with Mavericks

Shiboken has some issues related to c++11 functionality and it implementation in libc++. This bumps shiboken to the latest version and includes a patch to allow it build cleanly under Mavericks. The patch is currently under review upstream at:  https://codereview.qt-project.org/#change,69324.

For system python support, this change will also be necessary: https://github.com/mxcl/homebrew/pull/23866