More efficient round-up quotients

[cwgoes]

Ref https://github.com/cosmos/cosmos-sdk/pull/3750/files#r261452457

[elias-orijtech]

Hi! Is this issue still relevant?

[ValarDragon]

Its technically still relevant, but I wouldn't consider it a good use of optimization effort for the following two reasons:

• The method is rarely used
• We'd have to be very careful to ensure its state machine compatible

I think something that would be of higher impact is looking into if theres any way to make dec.Unmarshal() faster, as this dominates lots of protobuf deserialization times.

[elias-orijtech]

Alright, I'll close this as not worth the effort.