Parameters can be represented as data tables

- A new annotation @Table can be used to mark parameters as data tables
- The type of these parameters can be:
  - A two-dimensional array
  - A list of list (actually all types implementing Iterable are supported)
  - A list or array of POJOs, in which case the fields represent the
    columns, where the field names become the header of the table.
- Data table values are represented as a list of list in the JSON model
- Reporters present data table values as tables

Issue #52