Minor rename of a method argument.
Minor comment change.
Renaming of some html attributes.

More in line with the new "opml-import" nomenclature, instead of "data-import".
Renaming of several entities according to the new "opml-import" nomenclature, instead of "data-import".
More renaming "data-import" -> "opml-import".
Reorganized alert view fragments.

The alerts fragment was getting too big and unwieldly. Now it's been divided into smaller fragments grouped by associated functionality.
Renamed data-export to opml-export everywhere.