[BuildTools] Another rewrite of run_autotools

[Lou Hafer]

Folks,

	In response to comments from several of you, I've done another rewrite
of run_autotools. Changes of note:

  * In order for a directory tree to be handled as an independent unit, there
    are a number of autotools auxilliary scripts (install-sh, etc.) that must
    be present in some place where the autotools can find them (see the
    autoconf doc'n for AC_CONFIG_AUX_DIR). They will also be used later during
    configuration, build, and installation.
    
    The previous version was a bit too aggressive when it came to installing the
    auxilliary scripts. This rewrite will refresh them from BuildTools only if
    install-sh is already present.

    Which leaves the problem:  How to get them in place the first time?  Hence
    there's now an option, -i, to force run_autotools to copy in install-sh,
    etc.

  * The old (pre-Split) package organisation assumed BuildTools was present as
    an external in the top level of the package. In subdirectories, it is
    common to see `include ../BuildTools/Makemain.inc' in a Makefile.am (and
    there can be multiple levels of `..'). I think I've managed to keep
    compatibility with this. To do this without giving run_autotools an
    understanding of the hierarchy requires that the temporary BuildTools links
    that it creates are not deleted until the script exits.

  * You can once again specify a set of directories on the command line (my
    bad that this disappeared in the last rewrite). If you don't, the current
    directory (`.') is assumed. All directories are then searched recursively
    for configure.ac, and some filtering is applied to come up with a final
    set of directories to process. Use -nr to suppress the recursion. If you
    specify -nr and also specify directories on the command line, they are
    processed with no further checks. Be careful.

  * Specifying -h will get you a help message and exit  :-).
  
This revision is committed to BuildTools trunk. Give it a spin.

							Lou