Add simplistic analyzer for the openness metric

Just added a analyzer which parses the license file, too. Also some
fixes for smaller issues.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Write metric generator script as a Rake task

In order to simplify metric generation I have written a Rake task which
uses a metric template. I have also added the inverse script, for
destroying the metric again.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>