fixed initial configuration

The README file mentions to run $ ./configure first, but this fails for me on all of my various systems: ... error: cannot find install-sh, install.sh, or shtool ...

Running this first $ autoreconf -i would create these scripts, but unfortunately autoreconf fails: ... configure.ac:294: error: possibly undefined macro: AC_SYS_EXTRA_LARGEFILE ... onfigure.ac:466: error: possibly undefined macro: AS_AC_EXPAND ...

This can be fixed by adding AC_CONFIG_MACRO_DIR([m4] in configure.ac.