Selecting a measure also selects all spanners before it

Context: r. 74b4a45 self compiled with Qt SDK / Qt Creator.

Steps:

1) Load any score with some voltas
2) Select a measure after the voltas

Result: the volta indications before the measure are also selected. The same applies to other spanner types.

I am about to post a pull request to Github with a fix for this issue.

M.