Refine shared test styles.

Add and refactor with container-skin placeholder.

Add background color.

Tweak and refactor base and header type.

Minor whitespace.
Add sample ST2 project file section to readme.
Allow source scripts to support AMD.

AMD is preferred, but not required.

Remove obsolete AMD-specific versions of
extensions.

Minor white-spacing and reformatting.
Allow tip test to support AMD.

AMD is preferred, but not required. Uses custom
configuration, which can be a good sample.

Create a tip test script for embedded script.

Move embedded styles to tip styles.

Minor whitespace and markup cleanup.
Minor Grunt watch tasks note.