Clean up the soversion/flavour labelling of binary runtime packages.

Clean up the soversion/flavour labelling of binary runtime packages.
Split out a common wxPython package so the runtime support for it
doesn't need to conflict any more either.

Makefile.in was apparently committed from out of date bakefiles
so it is included here again too.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29635 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775