Update build instructions for new autoconf, GitHub The Linux build machine has been upgraded to autoconf 2.69, automake 1.15, m4 1.4.17, and libtool 2.4.6, so it is no longer necessary to recommend running autoreconf prior to building the source, if one is building from an official source tarball (as opposed to from a git sandbox.) Also, there is no SVN repository anymore (oops.)