Draft of new combined manual for Autoconf and Automake

[Gavin Smith]

I've uploaded my work on editing the Automake manual at
https://bitbucket.org/gavin_smith_/buildsystem-manual. It combines
material from both the Autoconf and Automake manuals. I was hoping to
present this material in a logical way that would make sense to a
beginner. As you'll see from the many TODO notes in the text, it's a
work in progress. The manual there is in PDF and Info format, as well
as the Texinfo source. I haven't done much work on this for several
months, so I thought it would be better to polish off what I've done
in case it is interesting to anyone, and in case it motivates me to
carry on work on it.

Much of this combined manual is copied verbatim from the Autoconf and
Automake manuals. Some sections, like those on shell script or
Makefile portability, I haven't touched, and have no desire to touch.
I made more changes in the introductory sections as well as organizing
the material as a whole into a scheme that I felt was understandable.
Some left-over material got dumped at the end in sections called
"FAQ's" and "Rationales".

I'd like to acknowledge some of the comments made by Arthur Schwarz on
some of the drafts. He rewrote a chapter of the Automake manual, here:
http://lists.gnu.org/archive/html/bug-automake/2015-07/msg00002.html,
which may or may not end up incorporated into this document.