This patch fixes some oversights missed in recent commits:
* `pers.json` entry in D2532/rP23746.
* `brit.json` entry in D2533/rP23781.
* Delete two auras rendered obsolete in D2686/rP23824.
* Tooltip and `mace.json` entry in D2867/rP23836.
* `maur.json` entry in D2821/rP23837.
* `sele.json` entry in D2858/rP23838.
* Indentation, tooltip, and `{civ}.json` entries in D2839/rP23840.
* Indentation, tooltip, and `{civ}.json` entries of Hellenistic Metropolis technology.
* Purged some non-existent things in various `{civ.json}` files.
This patch conflicts with D2222 and D2720, but those two are already outdated and need to be redone. If this patch is committed, that means less work for those.
[EDIT] Also added a history string and updated the technology tooltip for the Immortals. For more information, see https://iranicaonline.org/articles/immortals