All book control classes with the exception of wxGTK wxNotebook stored the
currently selected page in m_selection or m_nSelection (or, in wxUniv
wxNotebook case, m_sel) variable. Remove all of them and add m_selection
directly to the base class itself so that it can be reused everywhere.
Closes#12622.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65931 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is huge but there are no non-white-space changes in it.
Some files containing third-party sources (src/msw/wince/time.cpp,
src/x11/pango*.cpp) were left unchanged.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61724 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775