TODO:

small things:
* there are bug in the layouting of the table
* Elementar symbols should be small enough to fit the boxes
    (font problem?)

big things:
* backport the conversions from Kalzium (http://edu.kde.org/kalzium)
* backport more dataset from Kalzium
* make the colors configurable
* make elements sortable by their attributes (e.g. density)
* graph of attribute (e.g. ionisationenergie) vs atomnumber?

wishes:
* add radio active decay