Padding and margin values don't update in a editor panel

[caseyyee]

To reproduce:

1. Click on component.
2. Change margin or padding value in editor.
3. Click on another component, click back to original component edited in step 2.
4. Note that component margin and padding slider values do not update.

Great project, love it!

[caseyyee]

So, I did a little poking around to see if I could fix the issue and there is a UX related question that should be discussed.

I'm thinking that depending on values, we need to select the appropriate mode in the property controller depending on what values have been already set:

• left/right/top/bottom values are all equal, sets to all mode.
• left/right and top/bottom equal, sets to vertical-horizontal mode.
• left/right/top/bottom values different, sets to free mode.

Sound about right?