[Feature request] Queued toast evict oldest one to make room

Hi,

**Do you want to request a *feature* or report a *bug*?**
Request a feature

**What is the current behavior?**
So far **when there is a limit**, if a toast is queued it will remains as such until a visible toast time out and finally vanish. At this point the queued toast will be shown.

**What is the expected behavior?**
I'd like to have a gobal flag (at the ToastContainer level) to tell that if a toast enters the queue it must evict the oldest visible toast immediatly to make room.

Do you think this is something possible to do?