new design of startscreen and project menu
Merge pull request #249 from bheuer/master

finished work on startscreen
Merge pull request #1 from ilastik/master

Pull changes
added import statement for PathComponents (#252)
Merge pull request #253 from burgerdev/master

Fix for bug #252
enabled tracking workflow autodiscovery; improved ImportError handling in workflows init
more protection against missing tracking dependency
incorporate 5d threshold operator into synapseObjectWorkflow
add a colortable to output layer
returned small filtered components as colored
make objects layer visible by default
shell: Removed "Play Recording" menu item.  Must use command-line to play recordings.
object feature selection.

* new feature selection dialog.

* features implemented in plugins.

* new dependency, yapsy, for plugin management.
save selected object features
remove brush size names, #256.

Still todo: adjust "Size:" string in GUI to read "Brush size:"
use new signature of notify_failed
Moved OpH5WriterBigDataset to ioOperators.py (fixes #251)