Start work on stdio capturing
Drop (temporarily) HelenOS support
Stdout capturing (needs cleaning)
Add test that prints to stdout
Print the extra output
Capture stderr as well
Print number of tests to be executed
Merge branch 'capture-stdio'
Reporting related functions separated
Report results in TAP format
No need to count failed tests twice
Print multi-line errors as comments
Silence unused-variable warning
Let user choose whether to fork or not

It is possible to run the whole suite inside single process. That works
well as long as the test does not crash the program (e.g. by accessing
null pointer) or does not print directly to stdout. Otherwise, the
forked mode is much safer.
Extract error message from forked test
TAP report: distinguish stdio from error