[HatoholException] Show a debug message on a creation of a HatoholException object.

This is useful, for example, when an exception happens during an exception.
The current implementation cann't show information about the first exception.
Merge pull request #387 from project-hatohol/show-dbg-msg-on-hatohol-exception

[HatoholException] Show a debug message on a creation of a HatoholExcept...