simplified wrapInsImage
removed (broken) browser-sniffing in php-code to emit targeted non-wysiwyg-buttons
removed (broken) browser-sniffing in php-code to emit targeted non-wysiwyg-buttons further
wysiwyg.advanced is now always true, so default-template can always print the same editor-buttons
removed no longer used simpler functions like serendipity_insImage because the advanced version will now always get called