Always print seed at startup

[Axlle]

It would be helpful to always print the seed number so that the test ordering can be reproduced even when the tests fail to complete. Currently Subliminal tries to print the seed when after an error, but it may not be possible to detect all errors (exceptions, crashes, lockups, etc.)

I propose replacing "Tests are starting up..." and "Running tests in order as predetermined by seed 0123456." with the following messages:

• "Tests are starting up with random seed 4025613..."
• "Tests are starting up with predetermined seed 0123456..."