Fix a crash with depth 1 perft

Bug recently introduced in e215a88cddd16e09

No functional change.
Rename some UCI options

Thanks to Don, Miguel, Louis and the other people
of talkchess forum for the suggestion:

http://www.talkchess.com/forum/viewtopic.php?t=48612

Also sync polyglot.ini with current UCI options

No functional change.
Fix printing of PV info

It was erroneusly skipped after the
aspiration window rework.

Reported by Eelco.

No functional change.
Fix printing of PV info: take 2

Now last PV line is printed twice, fix that.

No functional change.
Sync with master

bench: 4507230
Retire enoughMaterial + Threshold 3 for trapped rook

Bundle 2 promising Tom's patches.

bench: 4558173