Multi-file upload issues

This is an umbrella issue to trigger further discussion on what actions to take.

1) when you upload multiple files, the dialog looks corrupted. There is only 1 delete button. See screenshot
2) documentation needs improvement:

• http://www.onehippo.org/library/concepts/editor-interface/image-and-asset-upload-configuration.html refers to html4
• Should we deprecate the flash upload? Wicket upload should be the only solution.