enable displaying object probabilities
Added option to load files by glob patterns.
allow multiple labels in object classification
fix layouting issues with mass file loader
when toggling the predicion layer, do not turn off live mode

fixes #116
tests: Fixed multi-image pixel classification gui test.
make carving workflow work with both 3d and 5d files

- use an Op5ifyer to get canonical shape an axis order
- assert for the correct meta information in both opPreprocessing
  and opCarving
- in OpPreprocessing, display any exceptions to the user
- make progress bar appear at once
- cleanup across carving files (unsued imports etc.)
tracking: updated tooltips
object classification test should work again
correct feature name for region center
tracking: implemented serialization
Merge branch 'master' of github.com:ilastik/ilastik into public_master
tracking: updated tab order
some changes