Patch Notes: Two Hands

Both fists up

Bare-handed, both fists are now on screen. Punches alternate between the hands: the hand that leads opens, the other answers if you strike again quickly, and the idle fist tucks in toward the middle while the other punches.
Each punch shows the arm that throws it, on its own side. Daggerfall's own fist art has punches for both arms, and each hand now uses its own.

Equip a one-handed weapon in each hand (swords, daggers, maces, war axes) and both are drawn and swung. You no longer swap hands to use the second weapon.
H now chooses which hand leads ("Leading with the right hand." / "Leading with the left hand."). It no longer costs a switch delay with both hands up. With one weapon it still swaps hands, as before.
A shield, a two-handed weapon, a bow, or a torch or lantern held in a hand still means one weapon, as before.
With weapon glow on, each weapon in a pair shows its own element (a frost dagger beside a fire sword).

A pair is quicker, not twice as strong. The next blow straight after a strike comes from the other hand, a little sooner.
The off hand (the one not leading) does 80% damage and has -5 to hit at Agility 50. Higher Agility shrinks the penalty to nothing; lower Agility raises it to -10.
A heavy weapon in the off hand swings slower (a longer follow-through after its hit).
The off hand's blows count as 0.8 of a blow for everything a hit sets off: on-strike enchantments, per-hit item and set powers, and skill training. A pair doesn't proc or train faster than its damage.
When one weapon attacks, the other lowers slightly, straight down (it never slides sideways and shows where the sprite is cut off).
Measured, a matched pair of light weapons deals about 9% more damage per second than one of them, and a heavier pair about 4% (the off arm feels the weight). That holds at any frame rate. In return you spend up to a quarter more fatigue per second and give up your shield. A light off-hand weapon (a dagger next to a longsword) is quicker but weaker overall.
The same rules apply in duels, sieges and the open PvP zone.

Running with nothing in either hand shows your arms pumping in step with your stride (on the head bob's own rhythm), using Daggerfall's own fist-and-forearm frames. The arm always runs off the bottom of the screen; no floating hands.
The arms keep running through a short hop, stay smooth when you stop and start again, and ease away when you ready a spell.
Works with every mod switched off. A punch thrown mid-run shows at once.

The Morrowind arms do all of the above:
- both fists punch in turn, each with its own hand;
- a pair of weapons shows the left weapon in the left hand, swinging with its own blows - now on the game's own skeletons too (they have no left weapon bone, so one is made by mirroring the right); the arm not attacking dips slightly at the shoulder;
- the arms pump while you run empty-handed.

TWO-HANDS: both fists, dual wielding and the running arms - sprite and Morrowind lanes, audited by @Lattymoy in #947

Full Changelog: app-v0.1.8924...app-v0.1.8940