Code changes done to support Selenium By class object with Geb
Documentation changes done for the support of Selenium By class object in Geb
Formatted the code according the Geb formatting conditions
Changes made based on the pull request comments.
Updated the contributor information
Geb is now built with Groovy 2.x so Spock dependency used in manual should be for that version of Groovy
Bump dep on junit to 4.10, use javadoc.io for resolving links to junit classes in javadoc
Merge branch 'by_locator_support' of https://github.com/menonvarun/geb
Some polishing after merging a pull request.