Merge Joona's razoring tweaks

Merge Joona's razoring tweaks
After proof testing on 3 different engines these
are the results:

Stockfish - Toga II 1.4.1SE +130 -132 =132 49.75%
Stockfish - Deep Sieng 3.0  +145 -110 =150 54.45%
Stockfish - HIARCS 12 MP    +94  -149 =150 43.00%

So it seems no regressions occurs, although also no
improvment. But anyhow this patch increases Stockfish
strenght against itself, so merge it.

Note that this patch not only adds back razoring at depth
one, but also increases razor depth limit from 3 to 4
because hard coded depth 4 limit is no more overwritten
by UCI parameter that otherwise defaults to 3.