Pandoc citations added through fzf (with the :CiteRef command) were
added in place, with an i. The usual case however is to write a
sentence, or part of a sentence, going out of insertion mode and wanting
the citation to appear *after* what was written.
Same story for insert mode citation (automatically called by typing
`@@`); also simplified its calling function somewhat.
Added simple maps for fzf finding note files from anywhere, searching
through wiki tags.
