Viewer fixes

This PR fixes issues related to embedding viewer on the static HTML content.
Doc on https://github.com/openmicroscopy/ome-documentation/pull/1038

1. Open following links and check if images are public:

  http://trout.openmicroscopy.org/merge/webgateway/img_detail/25251/
  http://trout.openmicroscopy.org/merge/webgateway/img_detail/9211/

  NOTE if they are not publicly available, log in as user-1 and keep window open during testing to share session.

1. Go to http://users.openmicroscopy.org.uk/~atarkowska/viewer.html
    - Using Show/Hide ROIs check if they appear. **Note: example has no preloader and it may take few sec to load ROIs**
    - Check if zoom, 1:1, fit buttons above image works. Test with scalebar and ROIs on.
    - Click on channel buttons, check if it turn on and off channels

1. Go to http://users.openmicroscopy.org.uk/~atarkowska/big_image.html
    - Is scalebar visible by default?
    - Using Show/Hide ROIs check if they appear
    - When ROIs on the image click ![32px_11](https://cloud.githubusercontent.com/assets/1065155/5215896/e001ac1a-7623-11e4-9d02-1d650419997b.png). Did viewer zoom in? Did ROIs and scalebar upsacale/downscale with image?

To test with iOS try iPad/iPhone or 
```
open /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Applications/
```