Cleanup some of the example code & docs

This commit makes a set of small adjustments to examples.

- Rework some of the comments to be more clear.
- Add links to the original source tree file.
- Rename some of the examples to make it clear the
  concept the example is intented to show.
- Move some common example functionality to the
  example utility file.

Change-Id: I858e0dbf72fe8cb40a05bfdbb0857720ffb71c7f
Merge "Cleanup some of the example code & docs"