Add missing dependencies on goog.array
Use in-place filtering for post-render functions
Use for loop for iterating over layers
Use in-place filtering for pre-render functions
Remove dependency on goog.array
Add ol.Map.getRenderer function
Add ol.renderer.Map.getCanvas function. Only valid with the canvas and webgl renderers
Remove stale dependencies
Export canvas map as jpeg image
Merge pull request #143 from fredj/get-renderer-canvas

Get renderer canvas
Export map as jpeg instead of png
Update readme.md
Merge pull request #145 from elemoine/readme

Update readme.md
Use goog.now() instead of Date.now().

Date.now() is not supported in Internet Explorer up to IE 9. The goog.now()
method can be used as a replacement.
Merge pull request #147 from marcjansen/goog.now

Use goog.now() instead of Date.now().
Export map.getLayers
Merge pull request #140 from twpayne/array-clean-ups

Array clean ups
Replace ol.overlay.Overlay with ol.AnchoredElement

This commit adds several features:
- rename of class to better reflect its behaviour
- full ol.Object support
- integration with postrender event for integration with animations and
  render loop
- minimised DOM modifications
- more precise positioning
- element placed in DIV to avoid modifications to user-supplied element
- correctly handle changes to the positioning property
Adjust border-radius of zoom buttons.
Merge pull request #150 from marcjansen/zoombtn-radius

Adjust border-radius of zoom buttons.