Shuffle tests inside a Suite

[marcelloh]

Description

With running tests, you can use "-shuffle on" to shuffle all the tests.
It would be nice if this could be the same inside a Suite.

Proposed solution

• running a Suite would do the same if that command line flag is set
  or:
• to be able to pass an extra parameter to the Run() like: suite.Run(t, &mySuite{}, true)
  or:
• to run a shuffled Run() like: suite.RunShuffled(t, &mySuite{})

Use case

I saw there was a solution earlier, that didn't get promoted into the final package.
(I would never promote an extra command line argument, since there is already one: "shuffle")