Create test specific markup in tests

Instead of relying on a shared dom structure, the tests should create (and destroy) elements as needed.
Copy social links script for hosted examples
Lint in build.py
Use more consistent directory structure
Merge pull request #382 from twpayne/move-files

Use more consistent directory structure
Example touch-ups

The strokeStyle property is now spelled strokeColor.  There is no sense in setting opacity to 1.5.  Moving map initialization up.
Properly maintain dirty state during animation

The previous logic assumed that if there were any tiles to render, the dirty state should be false.  The correct logic is to say that if we don't render during animation, dirty is true.
Merge pull request #325 from tschaub/dirty-animation

Render new vector tiles after animation completes.  This was previously happening during an animated zoom, but not an animated pan.
Merge pull request #395 from tschaub/no-test-markup

Create test specific markup in the individual tests as needed instead of relying on a common dom structure for all tests.