Fix bug in parsing variations

Fix bug in parsing variations

The moves parsed from a variation were stored in the moveList without
appended linefeed. This caused errors if the variation extended to
beyond the end of the main line,into a hitherto unused part of the move
list, as the linefeed was then not there from the overwritten move. As a
result moves sent to the engine were concatenated, triggering
illegal-move messages and bringing the engine out of phase.