This test takes as command line arguments several files with generated
repo indices and compares sets of 'requires' tags and 'provides' tags
without comparing version information.

There can be several types of result:

* each require tag has the corresponding provide tag - the perfect
  case;

* some require tags have no corresponding provide tags - the generally
  error case with found unmets;

* some provide tags have no require tags for them - usually the valid
  case, but user is encouraged to know what is the reason.
