Merge topic 'SIMPLEITK-416_SourceTarballData'

200a30d ENH: Add .ExternalData to .gitignore.
82eca71 ENH: SourceTarball.bash: also fetch from Midas.
Merge branch 'master' into next

Change-Id: I06c40bfd9573a4cb4ee3504c7f63bdbe6aa13add
Merge topic 'SIMPLEITK-417_LabelStatisticsClearMeasurements'

f65e122 BUG: Clear Statistics measurement maps when executing
Merge branch 'master' into next

Change-Id: Idd84f14d883311d6bd634c3e1ac61810e77314cf