[GSoC] Some patches for testsuite harness improvements and TAP support introduction

[Stefano Lattarini]

The patches I'm going to post in this thread have already been applied
to the 'GSoC/experimental/test-results-work' temporary branch, but now
I think they are mature enough to be moved to the "official" branch
'test-protocols'; fixlets and improvements can be done with follow-up
patches (I even think that this should be preferred to doing further
amendaments and tweaking of these patches).

Regards,
  Stefano