Do not update geocoder control results on special keys

[kirach]

A small change that prevents geocoder control from autocompleting (and update and re-render results) when special key (like escape, tab, enter, arrow keys) was pressed.

[kirach]

Guys, any feedback please? Do I need to change/add/remove something?

[jfirebaugh]

I wonder if we can use the input event instead. That would avoid needing to use keyCode which is non-standard, deprecated, and system and implementation dependent.

/cc @tmcw

[tmcw]

IE compatibility for input is pretty sketchy according to the MDN docs - no support for IE<9, and IE9 doesn't fire input when characters are deleted, which is a pretty common occurrence here.