ProCKSI

- Currently, further information for structuers (RCSB, CATH, SCOP, iHOP) are provided as links. They are available in the Dataset Manager checking only if the structure label looks like a PDB ID.
- In a future version, the user should be able to select in the Calculation Manager which sources for additional information he/she wants to query. This should be done as parameters to the Structures task. All results should be available from the Structures Manager or a specialised manager providing all available information regarding one structure.