Add Member and Method classes.
Did not create an Attribute class or the parameter class, because they are identical to the method class.
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/Element/EVisitor/EVisitorXMLWriter.java
	src/Element/Element.java
	src/Element/ElementTest.java
Merge remote-tracking branch 'origin/master'
Improved copy to properly mange links for Relationships.
Moved relationship's links to be an arrayList instead of separate links
Changed return type of Set<> to Collection<>. This will allow return of arrayLists or HashSets.
Added relinkChildren function to Diagram to find all missing links and either set them correctly or set them to null.
Updated visitor classes to call re-link on diagram and properly write Relationship
Added link options to the ElementClass
Added relinkChildren function to Diagram to find all missing links and either set them correctly or set them to null.
Updated visitor classes to call re-link on diagram and properly write Relationship
Added link options to the ElementClass
removed several FIXME's.
Merge remote-tracking branch 'origin/pr/21'

Conflicts:
	src/DiagramController.java
	src/Element/ElementClass.java
	src/Element/ElementRelationship.java
Merge pull request #21 from Zedzap/Link_updates2

Link updates2
Merge branch 'master' into undo_redo_merged

Conflicts:
	src/Element/ElementRelationship.java