Upgrade Flot Charts

[aalpern]

Miraculously, the Flot charts project is under active development again! (see http://www.flotcharts.org/blog/2018/02/04/flot-216-new-maintainers/). Upgrade to the latest version. This will likely require a bunch of changes.

• https://github.com/flot/flot
• https://www.flotcharts.org/
• https://www.npmjs.com/package/flot

Things that are likely to require changes:

• [x] Default time base of seconds, not millis: https://github.com/flot/flot/issues/1612. May need to add timeBase: "milliseconds". See https://github.com/flot/flot/blame/master/CHANGELOG.md#L43
• [x] autoscale renamed to autoScale
• [x] various series options are now in a series sub-object. See https://github.com/flot/flot/blame/master/CHANGELOG.md#L20
  • [x] flot-barnumbers needs updating
• [x] the d3 stacking plugin no longer works - that will require some updating
• [x] time and axislabels plugins now baked-in
  • [x] converted tick formatter to a plugin
  • [ ] Could look at using the new jquery.flot.absRelTime.js plugin (more flexible time formatting), which allows for time format specification as well, which would handle #451
• New logaxis plugin - does it change how log axes are specified?
• [x] Axis labels are messed up in tessera's charts
• [x] hover-over series highlighting causes weird rendering errors when axis labels are present
• [x] time series bar charts are rendering incorrectly
• [x] pie charts are not rendering at all
• [x] "- move backgroundColor and backgroundOpacity from legend settings to css" - might affect color themes
• [x] Update themes CSS to include axes, which are SVG now. https://github.com/flot/flot/blame/master/CHANGELOG.md#L76
• [x] Hover over is broken for pie charts (See https://github.com/flot/flot/issues/1645, currently in progress)
• [x] Hover over is broken for discrete bar charts
• [ ] Rendering error on horizontal discrete bar charts
• [x] Series highlighting doesn't work for time series bar charts, but I think that never worked