Version check snippet chokes on mftrace-1.1.19 (bug in STEPMAKE_GET_VERSION)

[Ed Catmur]

Reposting because no response last time, sorry.

checking for makeinfo... (cached) makeinfo
checking makeinfo version... 4.8
configure: creating ./config.status
config.status: creating config.make
config.status: creating config.hh

ERROR: Please install required programs:  guile-config >= 1.6.7 (installed:
1.6) mftrace >= 1.1.19 (installed: 1.1)

See INSTALL.txt for more information on how to build LilyPond

$ mftrace --version
mftrace 1.1.19

The bug is in stepmake/aclocal.m4 (and aclocal.m4):

AC_DEFUN(STEPMAKE_GET_VERSION, [
...
    ## grab the first version number in  --version output.
    eval _ver=\"\`("$1" --version || "$1" -V) 2>&1 | grep '\(^\|
\)[0-9][0-9]*\.[0-9]' \
        | head -n 1 \
        | tr ' ' '\n' | sed 's/\([0-9][0-9]*\.[0-9][0-9]*\).*/\1/g' | grep
'\(^\| \)[0-9][0-9]*\.[0-9]' | head -n 1\`\"

Of course, this only picks out the first two numbers in any version string,
so "mftrace 1.1.19" becomes "1.1".

At http://bugs.gentoo.org/show_bug.cgi?id=132706 we're currently using
        | tr ' ' '\n' | grep '[0-9]\.[0-9]' | head -n 1 | sed
's/\([0-9.]*\).*/\1/g'\`\"
but if keeping it as similar is possible is desired, it should be
        | tr ' ' '\n' | sed
's/\([0-9][0-9]*\.[0-9][0-9]*\(\.[0-9][0-9]*\)*\).*/\1/g' | grep '\(^\|
\)[0-9][0-9]*\.[0-9]' | head -n 1\`\"

This is fairly important to getting lilypond into Gentoo, so help fixing
this would be appreciated.

Ed Catmur