[tlbuild] Build instructions for clisp

[Karl Berry]

    Date: Thu, 8 May 2014 10:34:19 -0400
    From: Ken Brown <kbrow1i at gmail.com>

      http://www.tug.org/svn/texlive/trunk/Build/source/utils/xindy/README-clisp
      http://www.tug.org/svn/texlive/trunk/Build/source/utils/README

    These should probably be unified 

After looking at this again, I'm not sure about that.  Joachim's
instructions (utils/xindy/README-clisp) are about building
clisp-for-xindy in general.  My instructions (utils/README) are about
building clisp-for-xindy-for-tl, where I just want to give one path to
building the binary that is best for tl (ie, most independent of the
OS), and not explain lots of different ways to do it.

I will add something to utils/README mentioning the xindy info, at least.

Joachim, you want to mention libiconv and/or --disable-nls in your
instructions, and --disable-mmap on BSD, all of which we do for TL.
See the end of the utils/README link above for my text.
Also, the current clisp version is 2.49, up from 2.43.

Best,
Karl