Fixed issues found during visual testing

Updated correlation.fromDataSet => correlation.fromDataProvider
Removed vertical tick label orientation from correlation example
Added group name parameter to dataset.group example text
Updated library code after visual testing issues fixed
Merge pull request #246 from niksoper/gh-pages-dev

Updated website after library changes to allow charts to be drawn without data
Updated library code after adding date and version number to change log
Merge pull request #250 from niksoper/gh-pages-dev

Updated library code after adding date and version number to change log
Fix missing package dependency

- Missing ```grunt-zip```
- Packages reordered by ```npm```.
Merge pull request #258 from matthewdunsdon/web-fix-package-json

Fix missing package dependency for Website