ongoing minor bug fixes

[miserman]

Minor but potentially a little tricky:

• map background shapes only show up after being loaded by other means
• centered legend stays centered when switching to color by rank
• floating info (tooltip) can start flickering if the cursor moves over it fast enough
• floating info can stick on, since it depends on a mouseout to close
• the top legend indicator can sometimes be destroyed when passing under the cursor
• some invalid URL parameter settings can prevent loading
• the focus effect is not ideal on some elements (e.g., floating labels on select elements disappear)
• the table's auto scroll doesn't always highlight (probably due to virtual scroller)
• when a variable is missing a year within its time range, other years are not plotted when the missing year is selected #41
• with Plotly 2.16.1, traces sometimes stick around between variable changes
• sometimes freezes up when hovering over plot traces and both line.width and marker.size are changed; minor because we can just change line.width, but it would be nice to be able to change both
• freezes when moving too quickly from Plotly trace hover to another hoverable output (maybe only on Chrome, when the console is open)
• clearing selections with the breadcrumb (reset) buttons doesn't work with only tract selections (with no county selection)
• closing a combobox group is interrupted by mouseover of contained elements (which trigger an open)
• float-type measures are sometimes treated as integers, which shows up as varying decimal places that don't respect the digits setting
• ID selection does not trigger data load (for non-default datasets; but does apply once loaded)
• switching to a non-existent dataset results in partial changes