fixes error thrown in firefox
Fixed bug where scrolling and refocusing using the mouse would place the caret incorrectly on IE.
Fixed bug where you needed to hit the empty paragraph to get editor focus in IE 11.
Fixed bug where activeEditor wasn't set to the correct editor when opening windows.
Fixed bug where dirty state wasn't set to false when undoing to the first undo level.
Merge pull request #241 from poops/master

fixes error thrown in firefox on localstorage
Fixed bug where pasting in inline mode on Safari on Mac wouldn't work properly.
Added image option support for addMenuItem calls. Enables you to provide a custom image for menu items.
Fixed bug where content_css wasn't loaded into the insert template dialog.
Added new template_preview_replace_values option to template plugin to add example data for variables.