Language tags for directory entries should be orderable

[nathandyer]

Currently, the language tags for a directory entry are displayed on the website alphabetically, regardless of which order the tags were selected in.

Some organizations have expressed interest in having the ability to list the languages in order of the ones that they are best suited to deal with (for example, if an organization primarily publishes in Spanish and French, but still accepts submissions in Arabic and English, they might prefer for Spanish and French to be listed first).