Remove some unneeded html_safe calls

Those calls are not necessary because:

- `content_tag` calls it on it's output already: what could make a difference would be to call `html_safe` on the input of that function
- the concatenation `+` of `SafeBuffer` (returned by `html_safe`) is another `SafeBuffer`.
- `link_to` uses `content_tag`
Align the elements of a hash literal if they span more than one line.