Add notes about accessing library properties from a FirefoxTestCase
Add a link to library documentation in README.md
Fix up docs following move from browser -> windows in #18
Merge pull request #26 from chmanchester/docfix

Fix up docs following move from browser -> windows in #18
Merge pull request #25 from chmanchester/greenlight_docs

Add notes about accessing library properties from a FirefoxTestCase
Create base and browser window classes and update tests and documentation (#18)