Make (un)present button width dynamic

[erdnaxe]

The present and unpresent button width is fixed to 5.8em. This is problematic as the content might need more space. By removing the width attribute, the element takes the width it requires.

Screenshot before the modification: "Disable" is overflowing to the right the button.

[jech]

The point here is that we want the Enable and Disable buttons to have the same width, so that the interface doesn't move around when the user toggles.

[erdnaxe]

What could maybe be done is to always display "Enable" and "Disable" and then set the opacity. Doing this the button will always take the width of the longest word.