Ensure JSpinner text is selected on focus

[hinerm]

3d3b555 partially implements a solution for text boxes in a JSpinner to be selected on focus. It works nicely for tabbing, but sometimes on click selection happens but is then lost.

Presumably this is a race condition with queuing the text box selection and some sort of validation of the JSpinner. But it's not clear what.

There are many SO posts discussing this but none seemed perfect resolutions.

Secondary goals:

• Understand why we would want to select text on focus lost
• Test on OS's besides mac
• Do NOT rely on sleep statements to queue selection after any JSpinner validation has passed