wordfile: Rename class that fetch from http to file

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
voldemars: Rename translation buttons listener

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
gui: Move some gui IO code to their own classes and some other cleanups

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>