Nicer findFile &c behaviour in dired buffers

Fixes #149
Implement C-a (select all) for CUA

Fixes #167
Fix dired for directories with unicode files/dirs

We don't mess around with the ISO-* stuff anymore, it's Text all the way
down. This might break something on systems that don't use sane locale
but I have no means of trying.

Fixes #445
Go through a couple of TODOs