use presence of source_locale as alternative to status attribute and eliminate requirement to create links in two steps.
we'll need to change source_locale sometimes, so better not make it readonly, but embed_data should be readonly.
clean up link model specs.
make validation message clearer for missing title in source locale.
include embed_data in link json.
use a more difficult url in links request spec to make sure things are working correctly.
update link edit feature to use set source_locale instead of status attribute, which has been removed.
add methods to print urls in display-friendly format, and include in json.
harder example for links api spec -- need to CGI.escape the URL to correctly pass it through routing.
use link url as id on client, and make sure it's properly encoded.