IE Scroll Bar on Discover app covers scroll bar on spy panel

[LeeDr]

This might be similar to fixed/closed issue #4784

And this might also be a relevant reference http://stackoverflow.com/questions/16831751/ie10-stop-scroll-bar-from-appearing-over-content-and-disappearing

In IE 11, on Discover tab, when there is more than a page full of matching documents (almost always the case?), the main scroll bar appears OVER the page content instead of to the right of it like it does in other browsers. This makes it difficult to see or click on anything along that right side.
This includes;

1. the Logout Shield plugin link (half covered by scroll bar)
2. "hits" on the chart hit count
3. the little right/left arrow that shows the "count" legend. This is actually BROKEN on IE.
4. when you minimize the chart and see the spy panel, you can barely access the edge if it's scroll bar because it's under the big full-page scroll bar.

For #3 above, here's the arrow clicked in Chrome and you see the legend;

And here's the arrow clicked in IE (hard to even click on it) and you don't see the legend;

for #4 above, here's the one scroll bar on top of the other;

[LeeDr]

This is working OK in Kibana master and 5.0 alpha1. We could keep this open for a 4.x fix.

[tbragin]

Dup of #9649