Setting focus() should scroll to cursor position

[LucVanPelt]

Clicking on a toolbar select list scrolls the editor to the top.

Steps for Reproduction

1. Visit quilljs.com
2. add some lines to the end of the document
3. click in the toolbar on the line format select

Expected behavior: the line should be formatted and into view

Actual behavior: the editor scrolls to the top

Platforms: Chrome 50 on Mac 10.10

Version: beta 0.1

Solution: add "this.scrollIntoView()" after line 57 in core/selection.js