Make it possible to set a non-default wxPersistenceManager to use and allow
overriding of GetConfig() and GetKey() methods by making them virtual and
documenting them.
This can be notably used to allow porting of the existing code to use
wxPersistenceManager while keeping compatibility with the old settings.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69583 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
