Added configuration models and LTW ontology model.
Added method to get the main PropertyItem
Added RDF configuration file support and changed all methods evolving XML scrapping to new Java classes.
Changed configuration variables (prefix-uri maps and ClassItem list) to static final, because they only change their values once (on config) and are equal for all LinkedTagWorld instances
New version of vocabulary and OWL file included in a new doc folder
Changed every isLinkable to isClickable because of changes in ontology.
Merge pull request #1 from jonlazaro/rdfconfig

RDF based configuration support