Generalize tagging

[fgrunewald]

One rate limiting operation is whenever a processor has to loop over the complete molecule list and pick molecules based on certain conditions like are they solvents, are they build. It would be better to generalize the annotator processor of AnnotateLigands and tag the molecules and/or store the indices in dicts. The point would be to as much as possible reduce looping over the complete molecule list unless required.