Bugfix: crash when breakpoint was hit in eval()-ed

Fixed a bug where Node Inspector crashed when a breakpoint was hit in a code
run by eval(). This is happening in two cases:
- Node Inspector calls eval() to get more information about the debugged
  process. In certain circumstances it was possible that the debugger stopped
  inside this code.
- User types `debugger;` in the console panel.

BreakEventHandler was changed to resume the execution in both cases, as if
the sources were hidden.