Add new stack trace capture class

In this release, I added a cool widget for capturing diagnostic information: the StackTrack class. This class extends Throwable and it's intended to facilitate capture of the flow of execution that triggered system state changes that may lead to future operation errors. For example, an object that's no longer valid might get used subsequent to the event that caused it to become invalid, or a long-lived object may get discarded without corresponding resources being cleaned up.

For more details, check out the blog post that provided the implementation for StackTrace.