Add ability to use Mutex / Condvar from std.

[BratSinot]

Fix #138

[SamTV12345]

Would be great if this gets merged.

[sfackler]

What is the point of doing this?

If we're going to support non-parking-lot mutexes this should use antidote rather than reimplementig non-poisoning locks manually.

[SamTV12345]

I took a look at this crate. It's more or less the same code. So the question is what would be more comfortable for you? Maintain two projects or one. These two approaches are better than parking lot with their own dependencies.

[sfackler]

What is the point of doing this?

[SamTV12345]

See above

[sfackler]

Why are these two approaches better than parking lot with its own dependencies?

[SamTV12345]

Because having other dependencies means they need to be compiled during build which means longer build times. If this is already included in the stdlib this would not be the case and I could get a smaller docker image.

[sfackler]

How much does this change affect your build times and docker image size?

[SamTV12345]

Enough that I want to have as few dependencies as possible.