remove dependency on external image files

It seems to me that the current JS/CSS files (as used in the demo page) relies on some image files coming either from independent servers or from folders that are outside the current one and hence only in the server.
For coherence, future protection against rotten links and portability I think that any files needed should be included in the Kemia file set.

e.g. in kemia.css there are:
https://ssl.gstatic.com/editor/editortoolbar.png
../images/toolbar-bg.png ../images/toolbar_icons.png

and in kemia-whitespace-only.js:
../../../../images//rotate-cursor-32.png ../../images/rotate-cursor-32.png ../../../../images/erase-cursor-32.png ../../images/erase-cursor-32.png

I understand that devlopment is at an early stage, but the sooner you fix this, the least risk of having it there in the future.

(Based on the source code of the demo pages at 29 sept. 2010)