Follow @claytondaley's suggestion and pimp custom API actions
s/GPL/MIT/. Closes #1528
I want to be able to get all keywords for a specific URL.  While the function yourls_get_duplicate_keywords() exists, it returns NULL -- instead of a single keyword -- if yourls_allow_duplicate_longurls() is false.  This commit refactors the keyword logic from yourls_allow_duplicate_longurls() into yourls_get_keywords() so a keyword list can be obtained regardless of the state of YOURLS_UNIQUE_URLS.
Added sort (order by) options to new yours_get_keywords() function.