Merge branch 'as/test-tweaks'

Output from the tests is coloured using "green is okay, yellow is
questionable, red is bad and blue is informative" scheme.

* as/test-tweaks:
  tests: paint unexpectedly fixed known breakages in bold red
  tests: test the test framework more thoroughly
  tests: refactor mechanics of testing in a sub test-lib
  tests: change info messages from yellow/brown to cyan
  tests: paint skipped tests in blue
  tests: paint known breakages in yellow
  tests: test number comes first in 'not ok $count - $message'

diff --cc t/t0000-basic.sh
Simple merge

diff --cc t/test-lib.sh
Simple merge