Support CREAM token collection and distribution to the depositors on BSC.

[Donald-Nobel]

Refer to COMP collected from compoud.finance,

1. collect COMP when the amount available to collect is large enough, say 10,
2. sell them by AMM (uniswap),
3. put underlying asset into internal pool,
   so the profit will go to dToken holders.

On BSC, the the similar action could be triggered, since dToken connects to CREAM.finance, and CREAM token could be collected.