moved stuff to lazyflow, extended fillmissing gui
Merge pull request #423 from burgerdev/pr-fillmissing

FillMissing has detection layer and command line option
object extraction: added vertical spacer
manual tracking: added log output to gui
manual tracking: added gui control for automated tracking window
manual tracking: abort if overlap is too small
manual tracking: increased maximum for window size
manual tracking: added button to find untracked cells
manual tracking: moved automatic tracking to subthread, adjusted error handling
manual tracking: remove subtrack extended
manual tracking: some minor bugs
implemented new disabling policy for pixel classification workflow
make normalization optional to fix #408, #405
Revert "implemented new disabling policy for pixel classification workflow"

This reverts commit e411c86ff7dbae948782bd2b0076c24b119b2e37.