Fix display of page references when language is not specified

Fix display of page references when language is not specified

Using translateIfPossible with null language does not make sense (and
gives an error on console).

Using translateIfPossible there actually does not make sense at all: it
is only for string from layout files that may already be translated.

We use the buffer language when no language has been specified. It
might have been better to use the GUI language.

A consequence of the commit is that "elsewhere" will be in the po
files and now really translatable ;)