Fixed the parsing of sub-api descriptions. (1) When parsing a @SubApi line, it will now add to the apiRef list if not already there. (Before it was relying on having seen at least one operation first.) (2) When parsing an operation, the operation's description will no longer override the apiRef description if one already exists.
Merge pull request #40 from polyglot-jones/fix-sub-api-descriptions

Fixed the parsing of sub-api descriptions. ...