harness: cleanup tests to not override is_finished() where possible

If is_finished() cannot be converted into get_finish_string(), i.e.
is_finished() is a condition that depends on multiple output lines make sure
we call super().is_finished(line) on every line so that we catch Assertion
errors etc. that are checked for in TestCommon.is_finished().

Signed-off-by: Simon Gerber <simon.gerber@inf.ethz.ch>

harness: Remove support for $BUILD in test module names

This is not needed anymore as modules starting with a / are treated as
absolute and hence do not get the prefix.

Signed-off-by: Moritz Hoffmann <moritz.hoffmann@inf.ethz.ch>

Spawntest needs to cope with colorful output.

changeset: 1270:aa365ea1f4c0
user: Stefan Kaestle <stefan.kaestle@inf.ethz.ch>
date: Thu Feb 28 10:37:59 2013 +0100
summary: Added a harness test for spawning programs.