Permission denied error (403) on payload/token userID mismatch enforced.

deleteNode method and utility method in NodeDAO

Conflicts:
	src/test/java/it/inaf/oats/vospace/persistence/JobDAOTest.java

creator property write is allowed. 

Passes testSubPath() test in CreateNodeControllerTest now.

Deleted db_init.sql (we use the SQL code from the dedicated repo: https://www.ict.inaf.it/gitlab/vospace/vospace-file-catalog

for user injection and added test on write privilege by ownership.

Changed separator for group_write property to " " in 
CreateNodeController for consistency with NodeDAO

ContainerNode then throw ContainerNodeNotFound exception