Remove "Last seconds noise" filtering UCI option

This feature makes sense during development, but
It doesn't seem to make sense for normal users.

Also fix a possible race where the GUI adjudicates
the game a fraction of second before the engine sets
looseOnTime flag so that it will bogusly waits until
it ran out of time at the beginning of the next new game.

The fix is to always reset looseOnTime at the beginning
of a new game.

Race condition spotted by Tord.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>