Tuned version of TT replacement policy

Tuned version of TT replacement policy

If the used multiplier of 8 was any number larger than DEPTH_MAX
this would be a non functional patch.

STC 2MB
LLR: 2.96 (-2.94,2.94) [-1.50,4.50]
Total: 16353 W: 3216 L: 3066 D: 10071
http://tests.stockfishchess.org/tests/view/55a6d0630ebc590abbe1babd

LTC 8MB
LLR: 2.95 (-2.94,2.94) [0.00,4.00]
Total: 134618 W: 21276 L: 20716 D: 92626
http://tests.stockfishchess.org/tests/view/55a74d760ebc590abbe1bad6

STC 16MB
LLR: 2.96 (-2.94,2.94) [-4.00,0.00]
Total: 22549 W: 4257 L: 4178 D: 14114
http://tests.stockfishchess.org/tests/view/55a9a2f90ebc590abbe1bb16

Bench: 7372460

Resolves #380