Update session03.rst

- Grammatical typo
- Line 192, slide 12, is very long, not sure if the font can be shrunk
- Line 460, wrapped so it will fit on screen
- Line 835: assignment does not output, need to type the name explicitly
- Line 1169: typo, hexadecimal, not hexidecimal
- Line 1217: json.dumps produces output
Merge pull request #45 from fulv/patch-4

Update session03.rst

With thanks, @fulv
add answers to last weeks puzzler.
add link to html-only version of the slides for session03
Fix one typo.
Update session04.rst

I'm not sure about the change on lines 770-771, but it struck me as odd.  And then my suspicion was confirmed on slide 49 (lines 975-6), and the file wsgi_1.py.


Line 1022 says:
You may also want to consider using ``print environ`` in your application so
you can see the dictionary.

But the wsgi_1.py file already has a pprint environ statement in it.
Merge branch 'master' of https://github.com/UWPCE-PythonCert/training.python_web
HW3