Add shortcuts to jump to top & bottom of history.

The shortcut of jumping to top of history is for the request of #45950

The shortcut of jumping to bottom of history is added not only for
consistency, but also to be used for #38390, especially its comment #9
 and #10.

Patch by Jekyll Wu <adaptee@gmail.com>

FEATURE: 38390
FEATURE: 45950
FIXED-IN: 4.8
REVIEW: 102124