Filter button itself shouldn't be multiselect

[nathandunn]

• Button should be labeled "All" when nothing selected or the name of the filter
• button shouldn't allow multi-selection
• drop-down filter shouldn't overlap results if at all possible

From #1 (comment)

[pnrobinson]

@monicacecilia Is this issue still relevant? I do not understand what the action item is? Please close or provide details about what needs to be done.

[nathandunn]

I think that it was an awkward filter to have this me a multi-select (think of the way Amazon does this) versus a single select:

I wouldn't bother for a 1.0 release, but it would be better to convert it to a single select at some point.