showWidgets parameter for foldLines function

There are cases when widget could be a different repsentation of code, so while folding the code 
one may want to show widgets for hidden lines.

I added showWidgets parameter to foldLines, if set it allows widgets for hidden lines to be shown.
Here is a simple showcase where this functionality is needed:
http://uxcandy.com/~boomyjee/dayside/plugins/teapot-copy/