• Fix bug in getSelectedParentElement + Fix tests in browsers
• Fall back to shimmed insertHTML in cases where firefox throws
  when calling insertHTML
• Prevent "Argument not optional" error
• Prevent infinite loop after findAdjacentTextNodeWithContent
• Remove cleanups from contenteditable false areas
• Firefox fix: Don't modify value of input before calling execCommand()
• Fix selection issue for clean pasted html test case in firefox
• Add image drag and drop support