Let "texture" parameter set a texture path.
Refactor OvaleFrame so the code to update one icon is a separate function.

The OnUpdate script handler now calls OvaleBestAction to compute the best
action, then calls the UpdateActionIcon method to update the icons.
Middle-click on the minimap icon will toggle the script options panel.
Reorganize options to allow for an "enable icons" toggle.

The Visibility options group is now a subgroup of the "Icon Group" options
group, which has options for the bar of icons for the script.  There is a
master option "Enabled" which toggles whether the icon bar is
enabled/visible, and which triggers enabling the other options.

This allows for hiding the icons while still having the script processed
by Ovale.
Re-parent the options panel so it has independent visibility.

The "contents" frame containing the script options widgets had the Ovale
frame as it parent, so it was hidden when that frame was hidden.  Instead,
set the updateFrame as the parent so that hiding/showing the Ovale frame
only hides the icons and the green "move" bar.

This allows for hiding the icons but still allowing to toggle the options
panel via the minimap button.
Tag spells that are used as spell interrupts with "interrupt=1".
Add feature to flash spells on action bars using SpellFlashCore.

This feature requires that either SpellFlash or SpellFlashCore is
installed in the Addons folder.

This feature must be explicitly enabled in the Ovale options.
Update README to reflect current support for classes and new features.
Update localization data.