added concepts
code cleanup and minor changes
chg: int->long
adjusted to new structure of knowledgebase
new validation according to new kb-structure
new tests according to new kb-structure
added feature-ids
fix: setting of concepts
add: isSelfFulfilling()
add: hasConcept()
several bugfixes and refactorings
refactoring: constant names
removed buggy event
added ConceptValidator