- version bump
    - Sort rm commands output for mostlyclean-generic, clean-generic,
        distclean-generic and maintainer-clean-generic, so that the produced
        Makefile is not sensitive to the way Perl sorts its hashes.
    - Support `+' in the name of directories given to `include'.
    - Preserve spaces in the arguments of `compile'.
    - `missing' will no longer try to emulate a tool that is run with
        `--version' or `--help' as argument.
    - There is a new chapter about the history of Automake.