Fixed issues:

• #7168 : [IE9] Destroying an editor instance throws an error.
• #7169 : [IE9] Menu item has incorrect height.
• #7178 : [IE9] Read-only attributes do not work in IE9.
• #7181 : [IE9] Toolbar items are not aligned in v2 and Office2003 skins.
• #7174 : [IE9] Elements path does not load correctly when the editor is switched back from Source to WYSIWYG.