RF launcher demo

[jeremygray]

• provide a 'quit' button
• add place-holder tool-tips; could add more documentation here
• parameterize button creation: simplifies code, uses eval() but only for known values

[aroberge]

Seeing the removal of the repetitive code (I should have noticed as I started by copying-pasting code each time I added a widget), I feel greatly humbled (to not say dumb...).

[jeremygray]

Seeing the removal of the repetitive code (I should have noticed as I
started by copying-pasting code each time I added a widget), I feel greatly
humbled (to not say dumb...).

I feel happy to have my little code snippets included in your project! Some
people are deeply averse to using eval(), but I think it makes life more
pythonic here.

By reading your code, I'm learning about pyqt and python 3. Thanks for
putting this out there, I'm learning a lot from you, André.

[aroberge]

eval() is there for a reason ... and your use seems like an excellent reason to use it! (although, I just thought of a possible way to remove it ... if only to please the "purists"). And, your idea to have tooltips is excellent (I never used them with PyQt before) ... I may just have abused them in the latest commit!

[aroberge]

Yes, it seems possible to use eval. Since you used it, I suspect you did not know of the method I used.