Add Uninterruptibles support for Condition

[ChristianSchwarz]

It would be nice to have Uninterruptibles support for Condition.await() and overlaods.

So we could write

lock.lock();
try{
  awaitUninterrutibly(condition,1,MINUTE);
}finally{
 lock.unlock();
}

[cpovirk]

This is a case where this probably won't be a high priority for us but we'd be happy to take a patch. You might also be interested in Monitor, which includes waitForUninterruptibly.

[cpiotr]

Hey, I've created #3005 and it would be great, if you could review it.

[cpiotr]

Hey, I've created #3010 where I squashed commits into one and it would be great, if you could review it.

[cpovirk]

Do you care much about the Date (awaitUntilUninterruptibly) version included in your pull request? Even though we're just mirroring an existing API, we're always a little hesitant to even suggest that Date is a good idea, especially for elapsed time.

[cpiotr]

I don't care much about this one, to be honest.
Shall I remove it and repeat the process (squash and send PR)?

[ronshapiro]

No need to squash and create a new PR, just add new commits to the PR and we'll handle the squashing

[cpovirk]

We make the changes internally first, anyway, so I can just remove it from my local copy. No need to update or replace the PR.