reverted the --inplace addition and instead documented the use of

reverted the --inplace addition and instead documented the use of
--prefix and --exec-prefix to do the same thing.  I can't think of
any way to do this right now with one flag without making some
assumption about the users working habits.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18753 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775