Front enhancements

Hi,

I improved some little things on the front. It's a quite a mix of them in this MR, sorry about that, but otherwise it would have been really really small MR with very few in it...

Here is a list of the changes:

• Radio editor: changed a standard checkbox by the switch used in the App
• Corrected one wrong <translate> tag
• Modified the buttons with an icon to display the little divider between the icon and the text a it is used generally in the App but might have been forgotten on the other ones
• Modified the Radio Card to always display the button(s) on a new line after its owner's name as it looks better
• Modified the PlayButton to be the same height as the other buttons (it was a little bit too big before)
• Added one changelog fragment, don't know if it's necessary though...