updated the license for 2013
cleaned the dist.sh script thanks to ShellCheck
catching up with Varnish 4 breaking changes

With the release of Varnish 4 Technological Preview 1, the upstream
version `trunk' has been replaced by `4.0.0-tp1'. Without any match on
Varnish's version it would have fallen back to `3.0.0'.

The vmod's vcc file syntax has been changed to incorporate documentation
with rst, and generate two rst files (one for sphinx, one for rst2man).
Honoring this change breaks the build for Varnish 4.0.0-tp1.

The module already had the readme to generate the man page. The build is
now a little twisted to overwrite the readme for Varnish 4 builds.