Unused techs in 0ad

The following is a list of technologies inside the `simulation/data/technologies` folder of 0ad (http://play0ad.com) that at the time of writing this are not researchable from any buildings.

* `pair_cav_01`
 * `armor_cav_chamfron` - "Chamfron", copied to create `armor_cav_01` and `armor_cav_02`, and is virtually identical to the former and shares its genericName with both
 * `attack_cav_lance` - "Cavalry Lance", copied to create `attack_cavalry_melee_02` and is almost identical
* `pair_inf_armor_01`
 * `armor_infantry_hack_01` - "Quilted Body Armor", copied to create `armor_infantry_01`
 * `armor_infantryspearmen_pierce_01` - "Plywood Shield Construction"
* `pair_inf_armor_02`
 * `armor_infantry_hack_02` - "Laminated Linen Body Armor", copied to create `armor_infantry_02`
 * `armor_infantryspearmen_pierce_02` - "Reinforced Shield"
* `pair_inf_armor_03`
 * `armor_infantry_hack_03` - "Scale Body Armor", belongs to `pair_inf_armor_03`
 * `armor_infantryspearmen_pierce_03` - "Bronze Shield Facing", belongs to `pair_inf_armor_03`
* `pair_inf_armor_04`
 * `armor_infantry_hack_04` - "Bronze Cuiress Body Armor", belongs to `pair_inf_armor_04`
 * `armor_infantryspearmen_pierce_04` - "Silver Shields", belongs to `pair_inf_armor_04`
* `armor_trade_convoys` - "Trade Convoys", same genericName and cost as `speed_trader_01`, hasn't been used in-game for months
* `attack_champions_elite` - "Heroism"
* `pair_walls_01`
 * `buildtime_walls_rubble` - "Rubble Materials"
 * `health_walls_geometric_masonry` - "Geometric Masonry"
* `carthaginians/upgrade_rank_advanced_celts` - "Advanced Celtic Mercenaries", `cart` specific tech
* `carthaginians/upgrade_rank_advanced_iberian` - "Advanced Iberian Mercenaries", `cart` specific tech
* `carthaginians/upgrade_rank_advanced_italiote` - "Advanced Italiote Mercenaries", `cart` specific tech
* `carthaginians/upgrade_rank_elite_celts` - "Elite Celtic Mercenaries", `cart` specific tech
* `carthaginians/upgrade_rank_elite_iberian` - "Elite Iberian Mercenaries", `cart` specific tech
* `carthaginians/upgrade_rank_elite_italiote` - "Elite Italiote Mercenaries", `cart` specific tech
* `hellenes/attack_inf_spearfighting` - "Infantry Spear Fighting", `hele` specific tech
* `pair_inf_01`
 * `melee_inf_sidearms` - "Side Arms", copied to create `attack_infantry_melee_01`
 * `ranged_inf_irregulars` - "Ranged Infantry Irregulars", copied to create `attack_infantry_ranged_01`
* `pair_inf_02"
 * `melee_inf_spearheads` - "Iron Spearheads"
 * `ranged_inf_skirmishers` - "Javelin Thong", icon recycled for `attack_infantry_ranged_02`
* `pair_house_02` - Used to include `unlock_females_house` as well, which is still in use and has been de-paired
 * `pop_house_02` - "Manors"
* `persians/training_levy_cavalry` - "Levy Cavalry", the `pers` civ has a separate building for cavalry units, and this was used to get round the fact that `training_levy_cavalry` (the generic) was paired with `training_levy_infantry` (both of which are now defunct).
* `phase_city_pair_celts`
 * `phase_city_britons` - `celt` specific tech to switch to `brit` subfaction
 * `phase_city_gauls` - `celt` specific tech to switch to `gaul` subfaction
* `pop_civic_01` - "Dining Hall"
* `pop_civic_02` - "Public Assembly"
* `romans/decay_logistics` - "Roman Logistics", `rome` specific tech
* `siege_packing` - "Military Engineers"
* `pair_levy_01`
 * `training_levy_cavalry` - "Levy Cavalry"
 * `training_levy_infantry` - "Levy Infantry"
* `upgrade_rank_advanced_cavalry` - "Advanced Citizen-Cavalry"
* `upgrade_rank_advanced_infantry` - "Advanced Citizen-Infantry"
* `upgrade_rank_elite_cavalry` - "Elite Citizen-Cavalry"
* `upgrade_rank_elite_infantry` - "Elite Citizen-Infantry"

The following are not technologies by themselves, but group two technologies in a "pair". The technologies of all of these have been de-paired (in that the techs themselves hold no reference to the pair they were once part of) and as such these files are now next to useless.

* `pair_gather_01`
* `pair_gather_02`
* `pair_gather_03`
* `pair_gather_wood_01`
* `pair_heal_01`
* `pair_heal_02`
* `pair_heal_03`
* `pair_house_01`
* `pair_siege_attack_cost`
* `pair_siege_attack_pack`
* `pair_siege_cost_armor`
* `pair_tower_01`