Refactor timeout scaling factor initialization
In order to stabilize tests on (heavily loaded) CI infrastructure,
reasses scaling factor every three minutes. Also include (simple)
I/O benchmark to compensate for (overloaded) I/O subsystem of
CI slaves.
For details, see `Builder::TestReport::Result >> timeoutScale`
call %~dp0\..\..\..\projects\smalltalk\stx -Mold:64000 -I --abortOnSEGV --execute %~dp0\report-runner.st %*