`port install' from github tarball fails

[Werner LEMBERG]

> Don't be put off too much by this.  It takes only about 10 minutes
> to fix, if you care to.  I use it on every machine < 10.9 routinely.
> [...]

Thanks, Mojca and Ken!  Configuring with

  ./configure ac_cv_have_decl_rl_username_completion_function=yes \
              --enable-readline \
              --with-curlprefix=/opt/local

(cf. https://trac.macports.org/ticket/57160#ticket, which I've just
filed) gives me a `port' program that can download files from github.

> There is one hiccup. Updating macports with "sudo port selfupdate"
> does not respect the curlprefix.
> 
> So instead, "sync" macports instead of "selfupdating" it
> 
> sudo port -v sync

I have to use `sync' anyway since I'm running MacPorts directly from
the git repositories.


    Werner