Toggling the gutter no longer collapses the lines to the left

[MikeRatcliffe]

Toggling the gutter no longer collapses the lines to the left. This is easy to see using:
env.editor.renderer.setShowGutter(!env.editor.renderer.showGutter);

Resizing the window fixes them but strangely calling window.resize() doesn't. After resizing the window toggling the gutter again means that the line is on top of the gutter.

[nightwing]

onResize does nothing because width isn't changed
nightwing@c6748d9

this solves immediate problem but there's still several issues here

1. onresize doesn't update layers when scroller underflows
2. doesn't update ace_content when scroller overflows (this results in scrollbar flashing while resizing)
3. longest line needed for those is expensive (linear with file size, it should use change deltas here)

[fjakobs]

I think this is solved. Since toggling the gutter is not likely a fequent operation the flashing of the scrollbar and the linear time with line numbers should be ok.