Widget count changes

[codelogic]

In single column mode (when the page is narrow enough)

If there's one widget, make it span
If there's two widgets, make it only take up 50% (don't flip to 33 or 25)
If there's three widgets, go from 33 -> 100 instead of 33 -> 25 -> 100
if there's four widgets, go from 25 -> 50 -> 100
if there's more than 4... do whatever. (Default is 25 -> 33 -> 50 -> 100)

[codelogic]

The php is going to have to spit out classes into the html for the different behaviors.