Throw UnsupportedOperationException calling 'add' or 'set' methods using @Incidence@ or @Adjacency@ if direction is set to 'BOTH'.

Fix for https://github.com/tinkerpop/frames/issues/33
Code like this will now throw an UnsupportedOperationException:

```java
    @Adjacency(label = "knows", direction=Direction.BOTH)
    public void addKnowsPersonDirectionBothError(final Person person);
    
    @Adjacency(label = "knows", direction=Direction.BOTH)
    public void setKnowsPersonDirectionBothError(final Person person);
    
    @Incidence(label = "created", direction=Direction.BOTH)
    public Created addCreatedDirectionBothError(final Project project);
```

Previously this would have behaved in the same way as Direction.IN