Speed-O-Meter

# Speedometer 1.3

Compatibility release for WoW Classic Era patch 1.15.9, plus new display
options and accuracy fixes.

## Fixed

- **Addon no longer functions after patch 1.15.9.** The display was stuck
  at 0.0, mouse clicks were ignored and the options panel could not be
  opened. Patch 1.15.9 tightened validation on `SetFont`, which caused an
  error partway through loading and silently disabled everything defined
  after that point.
- **KPH readings were roughly 9% too high.** The conversion used the
  metres-per-second factor rather than the yards-per-second one. A yard is
  0.9144 m, so the correct multiplier is 3.29184, not 3.6.
- **Speed colour thresholds were wrong in KPH mode.** The walking, running
  and mounted thresholds were hard-coded MPH values but compared against
  whatever unit was on screen. Thresholds are now calculated as a fraction
  of base run speed and behave identically in every unit.
- **Settings could be lost on a disconnect.** Settings were only written at
  logout; they are now saved as they change.
- **Settings from older versions no longer break the addon.** Missing keys
  are filled in from defaults on load instead of being left empty.
- The "new record" chat message could never fire due to a comparison that
  was always false.
- The whole display frame is now clickable, not just the area covered by the
  text.
- Long checkbox labels no longer overflow the edge of the options panel.

## Added

- **Percent mode.** Speed can now be shown as a percentage of base run
  speed — 100% on foot, 160% on a basic mount, less when snared or dazed.
  Right-click the display to cycle KPH, MPH and Percent.
- **Hide when idle.** Optionally fades the display out while you are
  stationary and back in as soon as you move. Hovering the mouse over it or
  opening the options panel keeps it visible.
- **Speed records.** Your fastest walking, running and mounted speeds are
  tracked and shown with `/speed records`.
- Escape now closes the options panel.
- The display is kept on screen when dragged near an edge.

## Changed

- Updated for Interface 11509 (Classic Era 1.15.9).
- The speed unit dropdown is now a button. The old dropdown widget was