More options

[dav1312]

• Optimism
• 2-fold
• MultiPV options (explore all moves equally, give priority to good moves, or output from standard analysis [free multipv])
• Draw shift

[dubslow]

I like making optimism runtime adjustable, would make it easier to make kibitzers

[dav1312]

Looks like it doesn't help make the evaluation symmetrical

[dubslow]

It does help, it's just not the only contributor.

[vondele]

I don't like to add more options for these things. Less options is easier to reason about, to maintain and to simplify.