extended RRUtils

- added static getStatementFromSet method
changes on LogicalTable + new tests

- 'renamed' getSubject to getResource (i.e. made getSubject deprecated
  and added getResource which does the same as getSubject)
- added extraction of type information of a logical table, i.e. whether
  a logical table is an existing table/view or a SQL query
- added tests for the type stuff and for the getTableExpression method
Added some utility functions
added TermMap base class and made SubjectMap inherit from it