Tiny issues with the UI in debug mode

[Naereen]

Hello there again,

I noticed a few things that are not optimal in the UI of the online editor:

• when entering debug mode, the style for current debugged line and current edited line can overbox and hide the first cells of the table of debugged values:
  
• if debugging after importing a "large" libraries (like math.h), the list of debugged values is large. It could be nice to wrap it in a div or some resizable zone, like the editor, stdin and stdout areas (see gif demo)
  
• when debugging, the stdin and stdout gets pushed at the end of the page, after the end of debugged values list, but they could be closer to the textarea editor.

Thanks!
Regards from France, @Naereen