* stepmake/aclocal.m4: Store computed version in variable.

* stepmake/aclocal.m4: Store computed version in variable.

* configure.in: Export MAKEINFO_VERSION.

* config.make.in (MAKEINFO_VERSION): Add.

* make/ly-rules.make: Add makeinfo <= 4.6 workaround.

* Documentation/user/GNUmakefile: Only build info with images when
building web.

* GNUmakefile.in (install-WWW): Visit Documentation/user.

* stepmake/stepmake/texinfo-targets.make: Move info and texinfo
stuff from documentation-targets.make