[tlbuild] mktexfmt enabled

[Karl Berry]

As John M and others noticed:

    I can't find the format file `latex.fmt'!

It turns out that mktexfmt was disabled by default.  I changed that and
ran autoreconf to update all the configure scripts.

Now when I do a fresh Build, the resulting engines do dynamically make
their format files.  Hope it works for others too.

So, all you platform volunteers, can you please rebuild?  And then,
finally, I believe we are ready to start committing the binaries so
people can start doing further testing of the distribution.  So please
send me url's or do the commits using tl-update-bindir (or laboriously
reproduce everything it does to handle symlinks, etc.).

If you can build xindy, great.  If not, don't worry about it.

I am still working on the instructions for asymptote; in any case, it
will not be integrated into the build this year, so it will have to be
built completely separately, a la xz(dec).

As in the past, by far the simplest thing for me to deal with is a
"flat" tar file with the executables, with no directory components.
As in:
cd /your/texlive/karl/Build/source/inst/bin/*
tar czf /tmp/forkarl.tgz *

Thanks,
karl