Add xh_ribbon.cpp to MSVC 10 ribbon library project.

Fix linking errors when using wxRibbonXmlHandler.

Closes #15927.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75743 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775