FIX: crash in shell command when ipcluster_dir already exists
Merge pull request #200 from ogrisel/ipshell-existing-ipcluster_dir

FIX: crash in shell command when ipcluster_dir already exists
scimage: add liblapack-dev to default pkg list
Merge branch 'develop' of git://github.com/jtriley/StarCluster into datacratic_dev