Merge pull request #24 from Automattic/fix-23

Standardize capitalization of RuntimeException
Merge pull request #27 from Automattic/handle-404s-in-getjobs

Check Jenkins response in getJob() and return false for 404s
Merge pull request #28 from Automattic/add-crumbs

Add anti-CSRF crumb (token) support
Merge branch 'master' of https://github.com/jenkins-khan/jenkins-php-api