Allow only left click drag for legend motion. Fixes #801
Allow only left click drag for legend motion. Fixes #801

SasView/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,SasView/sasview,SasView/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview