career cast plugin fixes for issue #24 and #25

Fixed: issue #24 - CareerCast-based plugins are adding site base URL to
the job title
Fixed issue #25 - startuphire job post URLs are missing the domain (for
CareerCast plugins)
fixed issue#25 startuphire job post URLs are missing the domain

Also fixed issue where job_id for startuphire included the site base
URL incorrectly