Use ceil for round calculations

[4miners]

Currently we use that formula for calculating round:
Math.floor(height / 101) + (height % 101 > 0 ? 1 : 0);
We can replace it with:
Math.ceil(height / 101);
That will give us exact same results when height>=0 (always is).
Should be replaced in entire system, including SQL queries.

Issue pointed by @simonmorgenthaler

Edit:
For SQL queries: CEIL(height / 101::float)

[4miners]

Performance of aggregateBlocksReward SQL query is bad after changes, need to be fixed.