`M-x untabify` changelog and unix.cabal

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Update aux files `config.{guess,sub}` and `install-sh`

This updates the files to the versions bundled with GNU automake 1.13.3

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Markdown-ify README and add Travis-CI script

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>