Volta brackets do not anchor to nearest bar line

1. Drag-and-drop a volta bracket to a measure. Take care to vertically align the start of the bracket with a bar line

Expected behavior: Volta bracket should anchor to the nearest bar line

Actual behavior: Volta bracket anchors to the bar line to the left of your mouse pointer. This makes it difficult to align a volta bracket exactly with a bar line. If you accidentally drop the volta bracket one pixel to the left of the bar line then it anchors to the previous measure.

Discussion: This bug is a consequence of (revealed by) http://www.musescore.org/en/node/3544