Formatting changes (pep8).
Minor improvement to start thread code.
Merge branch 'master' of https://github.com/cmeyer/nion-examples
Add MenuExample.
Updated MenuExample to use selected data item.
Simplify menu creation.
Fix phrasing of Color Phase (remove 'Show' verb).
Merge branch 'master' of https://github.com/cmeyer/nion-examples