Made busy-indicator work within modules

[mmoisse]

Made busy-indicator work within modules, requires git version of shinyjs daattali/shinyjs@8627e85

[daattali]

Was wrapping each input in its namespace the only thing required to do?

[mmoisse]

Apart from using the latest shiny js which fix a bug when id is NULL, it is the only thing I changed

[daattali]

In that case I would prefer to mention in the README that the input names need to be wrapped in the namespace function if used in a module, but the vast majority of people don't use modules and I think this code will add extra complexity/confusion. If I'm not mistaken, there's also a stackoverflow question about this (maybe you asked it?) so if the answer is on stackoverflow I think that's good enough.

I do appreciate you taking the time to make the PR