Proposed update to POS Minting control parameters

POS minting is in need of an update. In order for YACoin
to maintain confidence of it's users, we must adapt to the
higher N values (now 15). The problem is that our core
holders of YACoin have difficulty managing their coin inputs
as their numbers grow. Chunks of coin get split up into
tiny insignificant pieces, and the client doesn't have time
to check each input for POS block creation. Coins pile up
longer then 90 days before they get interest awarded. This
is a huge problem, as it makes YACoin fail to deliver on the
promise of 5% interest on coins kept between 30 and 90 days.

The old rules were designed for a paradigm that no longer
exists for YACoin. POS blocks are no longer expected to
completely replace POW blocks in some utopia of energy
efficiency. There is no longer any need to split coins into
tiny pieces in order to generate large numbers of POS blocks
in order to "secure the network".

To address this issue, new rules are presented that change
how coins are managed when POS blocks are minted. First of
all, splitting is out. Nobody really needs or wants their
coins to be split up. If they do, they can split them up
themselves any way they wish using Coin Control. Second, the
combine feature will be boosted greatly. Instead of waiting
90 days for a coin input to be eligible for combining, only
31 days will do. And instead of the combine limit being POW
reward divided by 3, (which is about 16 now), the combine
limit is set to POW reward times 10 (around 550 at the
moment). These new rules should lighten the load for clients
performing POS minting by about 100X. And small chunks of
coin (including new POW minted coins) will be awarded their
5% much sooner after the 30 day waiting period as they get
sucked up by other POS blocks.

It should be noted that these new "rules" are completely
arbitrary and have no effect on block validity. Anybody who
can build their own client can change these numbers at will
without loosing their coins or getting their POS blocks
rejected. And the "secure the network" thing is ancient
history.