input.down alt fire, not crouch

gun alt fire is determined by the down key not the player crouch state
  (so you can control alt fire when in the air or stuck in a tunnel)
  I did this with text replace, so it could produce some bugs

harpoon
  automatically uses power ups that return to player
  will aim at harder to hit targets, and possible miss
  returns extra fast if it is far from the player
  bullets last a bit longer so they don't despawn early
  cd on miss fire lowered to 1.5s (was 3s)

bugs fixes

js/powerup.js

@@ -779,7 +779,7 @@ const powerUps = {
         if (tech.isTechDamage && who.name === "tech") m.damage(0.11)
         if (tech.isMassEnergy) m.energy += 2;
         if (tech.isMineDrop && bullet.length < 150) {
-            if (tech.isLaserMine && m.crouch) {
+            if (tech.isLaserMine && input.down) {
                 b.laserMine(who.position)
             } else {
                 b.mine(who.position, { x: 0, y: 0 }, 0)