small fixes for legends- and popup box

[knutole]

• Looks like perhaps the second, third item does not get its content description included (only title)?
• Perhaps wrap this legend with a border or something, make it look a bit more "set." Also, it's a bit unaligned vertically.
• Perhaps move the opacity slider to one line. As it is now, it takes up too much space.

[knutole]

Should perhaps remove this function also, and keep all css in one place: https://github.com/systemapic/systemapic.js/blob/master/js/src/panes/pane.map.js#L378 ??

[knutole]

@jorgenevil Can close this if fixed..?

[jorgenevil]

Not quite there yet :P

[knutole]

• [x] Fixed opacity slider to one line.

[knutole]

This seems all fixed. @jorgenevil ?? Let's close it!