* international/mule-cmds.el (locale-language-names): Map locale
language name `ca' to language environment `Catalan'.
* language/european.el: Add definition of language environment for
the Catalan language.
* leim/quail/latin-pre.el: Add quail rule to the `catalan-prefix'
input method to support input of middle dot characters through
composition (bug#18279).