Updated MultiField Primitive to automatically set sub-field names

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Updated CurrencyRange field type

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Added overlay widget

Signed-off-by: Tom Wright <tom@inflatablecookie.com>
Fixed empty legend rendering in fieldSet widget
Updated SearchSelectorDelegate to use overlays

Signed-off-by: Tom Wright <tom@inflatablecookie.com>