B.Protocol support

[yaronvel]

B.Protocol implements a community based liquidation mechanism for loans and transparent risk management protocol. We plan to deploy our own markets over Rari in the coming month.

In order to support our markets a small change in the Comptroller is needed. The change can be included also in markets that do not use B.Protocol, and in this case the default behavior is unchanged. More details on the internals of the protocol are available here.

The change was audited