Under PlayOptions.IgnoreCrossWords a play connected to the board through any
perpendicular contact, even one forming a non-word, because connected() reused
the standard rule's touchesPerpendicular test while cross-words were suppressed.
That let an all-new word merely abut the board sideways and be accepted, and the
generator, with relaxed cross-sets, offered such plays.
Require the main word to run through an existing tile along the play direction
when cross-words are ignored, and filter generated moves by the same predicate so
generation agrees with ValidatePlayOpts. Standard rules are unchanged.
Ilia Denisov