Modified the Library to be more friendlier towards the uuid value obtained through Table updates and the _uuid column.

This change involves the following :

- Populated columnschema for internally generated columns(_uuid and version) by default to the TableSchema (Refer RFC 7047 section 3.2)
- Added "uuid" field in TableUpdate, without which the applications were unable to get the Row identifier
- Moved the generic Object in OperationResult to Row<GenericTableSchema>. But this change alone is not enough to make Select operation
  work as expected. We need a more richer way to populate the "columns" in Row class during the Select response (Bug 1190)
- Modified OvsDBClientTestIT.java to use the uuid column obtained from open_vSwitch monitor in order to insert and delete Bridges during
  add and delete operation (Note that the current IT code updates the open_vSwitch row without this where clause).

Change-Id: Ie0a58c6e45be72993a52a93d8c4374eda72fe687
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>