I noticed that pagination library has the content ('first', 'last') that I think should be in the language files. Additionally might add to them, 'previous' and 'next' and in the library itself to give the option whether to display textual or only symbols.
By the way: CI documentation does not mention about the 'first_url' option.
Agreed that this is a good idea, though not necessary for 3.0.
Add language translation support to CI_Pagination (#1589)