Add parameter for AccuracyLayer in proto.
Incorporate top_k param into AccuracyLayer and check it's value.
Compute top-k accuracy in AccuracyLayer.
Use vectors instead of arrays.
Next LayerParameter proto id
Add unit test for accuracy layer.
Update name of last added param.
Comment-fix.
Merge pull request #531 from flickr/dev-top-k-accuracy

Measure accuracy as top-k (default to top-1)