All the codebase refactored.

Basically, each example was refactored to use require.js. Although it
can be further refactored (since all of the examples use the exact same
libs folder), that will be done later on, now that the set has been
completed.

Maybe I could do a cuter repo out of this, i.e., a repo showing the
evolution of the code from Example 1 to Example 5 (since that's what
the examples actually do: progress from the simple to the relatively
complex).