document tarball build process
document tarball build process

This commit was SVN r667.

shekkbuilder/hwloc,shekkbuilder/hwloc,shekkbuilder/hwloc,ggouaillardet/hwloc,ggouaillardet/hwloc,ggouaillardet/hwloc,ggouaillardet/hwloc,shekkbuilder/hwloc