Let's improve the dmd tester.

[Stefan Koch]

Lately,

I have been working quite a lot on DMD again.
(Thanks to my Employer who is using my experience).

One thing which makes intrusive changes to DMD, hard to do, is 
the testing "script".
Which executes and evaluates tests for DMD.

It greets you with a wall of text, in which passing and failing 
tests are happily coexisting.
Which means that seeing which test failed for example on the 
output of Ci service, in which you can't do a grep, is a 
multi-second barrier in ones development process.

I do believe that fixing that, will have a large positive impact 
on the stability and maintainability of dmd.
Which is important since it's still the main semantic engine 
behind D.

I am going to try and fix the tester, but help and suggestions 
are always welcome.

Greetings,

Stefan