I made this for me, but thought I'd share if you find it useful. I'm a user of Dash, which is a Mac and iOS product that lets you search for functions, classes, and variables and see the associated doc block. I made a Dash docset for Moodle 3.1, feel free to use. I'll keep it updated as I can. I'm also going to try to recompile the docset to include source inline.
Subscribe to the XML in Dash or Velocity to get updates: http://mjsamber.s3.amazonaws.com/moodle-docset/moodle.xml
The docset itself is located at http://mjsamber.s3.amazonaws.com/moodle-docset/moodle.tgz