a quicker way to resize JVM

sometimes you just want to restart the current kernel with a bigger JVM.
would be nice if there were a menu for this, without going all the way back to the options panel and changing the default permanently.
especially, just setting the default and then restarting the kernel does *not* give you a bigger heap.
you need to close and reopen to get the new size. this is too hard.

Kernel Menu → Restart with JVM options...

that opens up a dialog with our pre-existing options panel plus the text "Do you want to restart the current kernel with new options? All variables will be lost."