Add debugging option to include the SQL queries in the output

[mingfang]

It would make debugging and learning somebody else's SQLPage site easier if I can hover over a component to see the SQL that was used to generate it.

For example, when I hover over a button like this

I would see the SQL in a popover like this

[lovasoa]

That would indeed be cool! But also a lot of work to implement :) I think we'll focus on important much requested new features at first.