Copying animal.txt files to software engineering directory for use there.

Copying animal.txt files to software engineering directory for use there.

Expanded lesson plan in dev_notes.rst and added exercises to README.rst

W. Trevor King: I reformatted the commit message from the original
3a1b378 so it fits better into --oneline logs.  I also turned this
commit into a merge so we can trace the copy, using:

  $ echo 081da9ef5959c5abdb8fefbdc8efc701d6a957c3 \
  >   d3bcf0219b92c2cfdd19239d2bf75de4ff26e579 \
  >   6bc0a0bef5d364b59a3927492f025a6c3676656d \
  >    > .git/info/grafts
  $ git filter-branch
  $ rm .git/info/grafts