Fix FT glyph outline to path conversion

When the start point is not on the curve, the end point will be
used as starting point for the QPainterPath, if it is on the curve -
if it is not on the curve, the mid point between start and end point
will be used. The origianl start point will still be used as a control
point for the first bezier curve.

Task-number: QTBUG-38601
Change-Id: I90e07f1141288873263f1f12fa51e6a248d0804f
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>