finish renaming contributor/user to agent, move currentperson back to ct, make currentuser return a user object instead of a 303
Merge branch 'master' into couple-child-relationship

Conflicts:
	gedcomx-model/src/main/java/org/gedcomx/Gedcomx.java
	gedcomx-model/src/test/java/org/gedcomx/rt/GedcomxModelVisitorBaseTest.java