Shorten timeout duration on initial tooltip appearance

[dpmccabe]

There is a very helpful mouseover/hover event on nodes and links that shows the counts of those elements. I'm noticing that there is a 1000-2000ms delay on the first tooltip appearing when I hover over an element. When I move the cursor to an adjacent node/link, the new tooltip appears almost instantly. If I move the cursor off of the plot and back onto an element, there is again a long delay.

I've forked the repo but can't find where these timeout lengths might be set. Could you lead me in the right direction? Thanks!