[symfont] Handle closePath()
[symfont] Handle closePath()

Apparently some draw() implementations expect closePath() to
draw a line to the contour beginning.

In fact, looks like fontTools's TrueType draw() always does the
lineTo() before closePath(), but the CFF draw() doesn't.

As raised in
https://github.com/behdad/fonttools/pull/618#issuecomment-225314022

fonttools/fonttools,googlefonts/fonttools