Fix block reward

[poiuty]

Block reward is controlled by Moore's law: 2222222/(((Difficulty+2600)/9)2) => does not work any more.
(because now high diff (ASIC mining))

Also GetMasternodePayment => max value

[schinzelh]

nACK as in #730

[UdjinM6]

@schinzelh well, there are few pro points I can think of actually:

1. it's another implementation and it doesn't break historical validation anymore
2. unlike in March (when ASICs were only a possibility) now we can be pretty sure that difficulty is never going to drop that low unless Dash fails completely - just few 100s of ASICs now provide same amount of hashrate as the whole network back then.
3. it's definitely a hard fork but old clients are going to be obsolete in 12.1 anyway
   One con I can think of is:
4. I guess that this change does not actually bring any performance gain but rather it is purely visual/algorithmic change for future blocks (which might be not that bad itself actually).

[schinzelh]

@UdjinM6 granted the implementation is better than the last one i still question the rationale.

The current block reward is more or less static at 3.88010205 Dash due to high difficulty (actually it's the case for difficulties > 2800) - but why should this get changed?

When @evan82 created the original formula in Feb 2014 he did some projections on how many coins will be minted. He floored the minimum coins to be created at 5 Dash/block, regardless of difficulty

a5b8194

 if (nSubsidy > 25) nSubsidy = 25;
            if (nSubsidy < 5) nSubsidy = 5;

One could argue that Evan did exactly the same adjustment for CPU --> GPU fork, moving the floor from 25 to 5, but i still don't see why we need another adjustment for GPU --> ASIC now. Maybe i am missing something, but what's the crypto-economical rationale to reduce subsidy depending on difficulty in 2016?