Up the max depth

No reason for this to be so shallow now that we have a proper timer.
Proper xboard POST output

We don't actually look for POST, but w/e. Much easier to look at the
output in the xboard window instead of in the terminal.
Print PV only to the current ply, even if we have more
Use strict inequality for transposition table eviction

Based on quasi-quantitative experiments based on number of nodes
searched in a simple opening.
Consistently fail-soft

AIUI, fail-soft vs fail-hard doesn't matter a whole lot, so let's at
least be consistent. I think fail-soft is supposed to be marginally
faster but has some transposition table instabilities -- but I find it
easier to read when looking at the code, so w/e.