add empty string-array when parsing empty line from csv
added a bunch of stuff
image loader should not load all at once, new images
return array indicating successfull conversion, use openbabel 2d conversion for mixtures
adjust to new imageloader
add new constructor
make nodes expandle, minor improvements
adjust to new image loader
small extensions
add icon with border and string as icon
add is-mouse-inside test
fix mixt detection for smiles when building ob3