Currently the Mauryan elephant archer has `template_cavalry_ranged_archer.xml` as its parent, but changes many stats, including removing the Cavalry class.
This is problematic, as tweaking one (e.g. D2585) would affect the other (D2575), something that's easily overlooked.
This patch therefore introduces separate elephant templates, so horse and elephant archers no longer depent on each other, making things easier for balancing, mods, and future additions.
D1035/rP20649 (kennel) and D1036/rP20682 (maceman) were similar patches.
[EDIT] Further changes:
* included footprint changes from D2496
* made it more similar to `template_unit_champion_elephant.xml`:
* removed slaughter attack
* removed wedge formation
* gave it the same sound groups
* increased vision range to 100