Torchagent flags (#1263)
Torchagent flags (#1263)

* Add two flags to TorchAgent to enable access to existing features: 
--use-reply to use either labels or model's own previous replies; 
--add-p1-after-newln to move the __p1__ token to the last newline
facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI,facebookresearch/ParlAI