Improved Readability of Material

This is a non-functional change that simply changes the look
of the code to help clarity.

No functional change.
Revert "Check for easy move just once"

This reverts commit a24da071f0d6128c633febab7df55f14475217c3

Seems a regression when tested against 2.3.1

With this patch, have after 20000 games at 60+0.05, we have

ELO: 13.42 +-4.8 (95%) LOS: 100.0%
Total: 20000 W: 3746 L: 2974 D: 13280

Instead with the patch reverted:

ELO: 16.62 +-4.8 (95%) LOS: 100.0%
Total: 20000 W: 3816 L: 2860 D: 13324

Although we are within error bounds here we take the conservative
approach of not introducing changes that are not proved stronger
It doesn't mean that the change shall be weaker, simply that we
don't want to take any risk.

No functional change.
Further increase SEE prune depth

After 16000 games at 60+0.05
ELO: 2.89 +-5.4 (95%) LOS: 96.5%
Total: 16000 W: 2775 L: 2642 D: 10583

bench: 5442365