Touch snag picks up planet and tape measure

[KatieWoe]

Device
Dell
OS
Win 10
Browser
Chrome
Problem Description
For phetsims/qa#505. Bug does not happen in published version.
It is possible to snag the tape measure while already dragging another object. This does not occur in the opposite direction.
Steps

1. Go to the second screen and go to the Earth+space station scene (easiest to see)
2. Turn on the tape measure option
3. Using touch, pick up the planet
4. Drag the planet over the tape measure, so that your finger also passes it over

Visual

[samreid]

In discussion with @arouinfar, we agreed this would be important for the RC but not necessarily for the dev version. But if it is easy, dev version would be nice!

[samreid]

Proposed fix committed, @KatieWoe can you please verify in master?

[KatieWoe]

Looks good in master.

[samreid]

Thanks, closing.