Using `XXX_VERSION_XXX` in the package.json caused `npm install` to
fail. So I’m replacing it with 0.0.0 which will allow `npm install` to
work and still be easy to replace during the deploy process.
- Added /dist/ folder to `.gitignore`
- Replaced references to version number with `XXX_VERSION_XXX`
- Replaced all-release `CHANGELOG.md` with per-release `changelog.txt`
- Removed `release.sh` script
- Added build task to `gulpfile.js`
- Updated `npm test` to build the distribution files before testing
- Updated the dist file header and made it preserved across both
minified and unmagnified files
