Show window sizes
Fix dimension overlay. Update dimensions on view resize

* Positioning an NSView over a WebView then scrolling the WebView causes weird UI artefacts. The dimension labels have been moved to just below the WebViews now.
* Dimension labels now resize on window resize and when split divider is moved.
Remove unused code
Allow webview widths to be resized down to 100px
Merge pull request #3 from jackbot/master

Show window sizes