Feat/smooth action

[cmhulbert]

This ended up being a large PR, containing much more that just the smooth action. Some notable changes:

features:

• smooth action
• change default mesh settings
• change default screen scales
• detect when a container/dataset is not discover-able from a project, and prompt the user to update the location
• allow removal of source state during deserialization of a project if an error occurs
• only use N5Readers by default, and only N5Writer when necessary (if possible)
• configuration of SAM parameters
• configuration of tmp and cache dirs
• modify selected fragment/segment/last selection directly
• re-enable mouse controls for merge/detach fragments
• better feedback for new label source with too many scale levels

performance:

• parallel mask apply and commit
• use animation timers for repaint request
• label-multiset improvements

fix:

• improvements to rendering (double buffering, and partial updates)
• rendering bug with non-thread safe labelMultisetType.copy()