Fix wxDynamicLibrary compilation under Solaris.

Add const_cast<> needed for the call to dladdr() to compile.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76694 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Allow using wxALIGN_CENTER in XRC for wxStaticText.

Only wxALIGN_CENTRE was allowed previously in the XRC, while both worked in
the code and also even in XRC but for wxSizer alignment.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76695 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775