Fix TextSerializer to skip inline roots (like annotations)
Drop broken creation of a text/html version for the clipboard for now
Put custom data into drag handler instead of built-in nodes text extraction, concentrate mimedata export in new gui.MimeDataExporter
No longer needed to pass focus explicitely back for IE in synchronizeWindowSelection
Merge pull request #275 from kossebau/noAnnotationInPlainTextCopy

Enable simple cut, copy & drag of selections as plaintext, drop broken support for richtext variants
Support different selection view renderers

In certain cases it is useful to be able to swap out the technique used
to render cursor selections on the document. For example, SVG polygon
based rendering interacts badly with mouse events on the WebKit build
shipped on MacOS X 10.7.5.