Beginning specs for Wordpress

Added model for Wordpress service

Added very very basic Wordpress cross-posting functionality.

Added markdown support to post body

Fixed Wordpress::MAX_CHARACTERS problem

cleanup

Added default settings for Wordpress OAuth

Added default settings for Wordpress OAuth

Added Wordpress to configured services spec.

changelog changes

Added Wordpress service functionality, for cross-posting to OAuth-enabled Wordpress.com or Jetpack-enabled Wordpress.org blogs.
Merge branch 'feature/4100-add-support-for-posting-to-wordpress-as-a-service' of github.com:andrewcsmith/diaspora into feature/4100-add-support-for-posting-to-wordpress-as-a-service