DataSelection: Don't show 'internal path' column unless some datasets are hdf5.
Fixes #384
Carving: Initialize render manager with 3d shape (not 5d).
Along with bheuer's commit 38a8a08f8, this fixes #365.
setup.py: add the ilastik icon of the startup screen
startscreen layout: added spacer
startscreen: set up projectManager before initializing the open file buttons
carving gui: implemented context menu for labeling applet
shell: redo all control commands / gui signals when closing a project
Merge remote-tracking branch 'origin/master' into trainable-tracking