[PATCH] Visualise auras

[sanderd17]

The patch added provides a way to visualise auras. When you select an entity with an aura, it will add icons to the affected units (similar to the status bars).

Currently implemented for the temple auras only

[sanderd17]

Place the icon in binaries/data/mods/public/art/textures/ui/session/auras/heal.png

[sanderd17]

I cleaned up a lot of the aura code to a newer spiderMonkey version.

No the statusbar saves the entities causing an aura change with an icon. The GuiInterface still saves the entities that currently have status bars, so by intersecting those two sets, you get the icons to be shown.

Apart from that, it's only a matter regenerating the sprites at the right time. So either when selection changes, or when aura application changes.

All functions are made to return as early as possible. So if there are no changes, calculation should be pretty fast.

[sanderd17]

In 16611:

Visualise auras by adding status icons to affected units. Implement the visualisation for the temple aura. Fixes #3180