Starting GUI for watchsubs settings

First implementation. Only GUI items were created.
Still missing icons and connections between each component.
Testing translation

Adding all necessary to translate app to pt-br.
Adding icons.
Updating resources.

- Replacing SVG icons by PNG.
- Created translation file for English
- All icons and translation files were added to resources file
Connecting widgets to related actions.

Now dialog has the ability to add/remove items to folders list.
Merge branch 'master' into settings-gui
Starting settings model
Deleting unnecessary __init__
Merge branch 'master' into settings-gui
Integrating settings model and dialog.