Move beginner course over to master
get rid of lots of justs, too many justs!
Add todo example
add notes for enamples to add
 Update Todo demo
Docfix: most shape functions take Float, not number args

Looked at and manually tested all functions in Graphics.Collage with
arguments involving the type number.  Only the shape creation functions
(except for polygon) took Floats and not numbers as documented.
See
https://groups.google.com/forum/?fromgroups=#!topic/elm-discuss/sqFIM6A2zIU
for the discussion.
Merge pull request #52 from cstork/docfix

Docfix: most shape functions take Float, not number args
Major overhaul, rewriting almost everything
Minor tweaks and clean-up
Slightly improved wording
Fix some typos

I don't know how to spell compatible.
Cite Laszlo, clean up definiton of Interactive Programming
Minor changes in wording
Word fiddling
Switch to trying to use html5 for FF bug with youtube videos
Fix spelling mistake
Command that the video is watched
Run on as many cores as possible
Get rid of dead code
Serve static files in the first frame of the editor