v4.0.12

Bug fixes

• Fix reporting of errors during startup (c178291)
• Fix an issue with restarting failed pipelines involving a map call
  over maps (cde0239)
• Fix an issue with mrjob hitting a self-imposed address space size
  limit when running with --monitor (68756c6)

Web UI Improvements

• Change the color used to display disabled stages (f3ee627)
• Add a button to the web UI to hide the sidebar and make the graph display
  larger (75a63f6)

Other improvements

• Set a few more environment variables for limiting threads
  (2dac501, b10737d)
• Log a few environment variables to detect running on HTCondor (1ea97ef)
• Add support for self-profiling of the binaries, and enable PGO for a few
  of them (d6cade9)
• When running with --zip, enable compression for larger metadata files
  (06bfc8b)
• Assorted updates to dependencies.