fix($compile): call `normalize` on nodes for cases when browser creates ...

...multiple text nodes when parsing HTML

When IE 11 parses HTML, it occasionally splits text into adjacent sibling text nodes. It's difficult to reproduce, but we have some screenshots of it happening: https://dl.dropboxusercontent.com/spa/4slnjubp16y5phq/3f-ld80p.png

While this is illegal according to the DOM spec, it happens anyways and should be dealt with. Angular currently can't deal with this.

Calling `normalize` when compiling a node addresses this issue. Test included.