Dimple support for AMD RequireJS

# Add support for AMD RequireJS to dimple.

This pull request adds AMD and RequireJS support for dimple.

Scaffolding changes to support this were done to `begin.js` and `end.js`  with the require/define/exports stuff happening up in `begin.js`.

> NOTE : Since D3 only introduced AMD/RequireJS support after the version that dimple was previously using, this change required an **update to the version of D3** that dimple uses, and the latest version has been put in.  Changes have been made to the plumbing to support including d3 with a version number, see Supporting Changes below...

## Supporting Changes

- Gruntfile modifications to include globals in JSLint for RequireJS and Jasmine
- Gruntfile Karma RequireJS support and changes to not include script tags for required dependencies
- Gruntfile Example Scripts to have script tags generated to support later changes to version numbers of both d3 and dimple
- Example Templates modified to include a script tag placeholder, rather than just a dimple script version placeholder
- Related Rendered Example changes
- d3 license file added and files used as is with version number in filename
- Karma `test-main.js` RequireJS bootstrap file added
- Spec added to test that modifications to support RequireJS actually work!
- **Old failing specs in the project have been marked with "x" to exclude them from Jasmine and the Karma test runner.** *We'll need to pick this up and check why they aren't executing in current version*