Merged.

Go ahead.

I prepared a small patch at https://bitbucket.org/jendrikseipp/downward/pull-
request/7/log-number-of-axioms-and-goal-facts/diff

Can I merge it?

Number of goals is interesting.

The metric doesn't really matter in the way we use it; I wouldn't write
something about it.

This issue has mostly been fixed in a different issue (can't find the number 
now). As far as I can tell the only missing info in the translator output is the 
number of axioms, right? 
What about the number of goal facts and metric?

For analyzing the translator and preprocessor performances it would be nice to
have more information directly available from their logs. That way we do not
have to parse e.g. the output.sas and output files.

The preprocessor outputs something like:

19 variables of 19 necessary
2384 of 2384 operators necessary.
0 of 0 axiom rules necessary

But this information should probably already be available in the translator log
and be better formatted.

Other values that come to mind are: 

* Number of arcs in the causal graph
* Number of facts
* Number of derived vars