AcquireWithin should take a context.Context

[kevinburke]

It would be easy enough to wait for either ctx.Done() or for a resource to become available.

[abiosoft]

This was written long before the context package. I plan to refactor it to take a context.

[abiosoft]

I'm thinking of adding AcquireContext.

[abiosoft]

Now there is AcquireContext and you can use a context.WithCancel if required. https://godoc.org/github.com/abiosoft/semaphore#Semaphore.AcquireContext.

AcquireWithin has also been modified to simply use a context.WithTimeout.