sprites: make hatchling/octoball explosions snappier. (#1220)

Something that's bothered me for a while now: the hatchling dies, it slowly oozes blood and crumples, the fireball explosion sound plays in the middle of all that bleeding and crumpling, then it slow-motion explodes in total silence.

Part of this the problem with the way the lost soul death is hard-coded - 6 tics per frame is just way too long for any decently snappy explosion. At best we can have like 2 actual "exploding" frames and the rest is just the bits floating in midair slowly fading away.

This PR skips the bleeding frames entirely in favour of what looks like a failed attempt at getting in one last attack, then a quick explosion right on the A_Scream frame followed by a few frames of that ring of glowing gore bits fading into nothing.

A similar issue to the hatchling death animation exists with the octaminator projectile as well. The lines coming out of the current B frame still imply an explosion rather than a lingering cloud of debris.

buildcfg.txt

@@ -1477,9 +1477,9 @@ FATBB2B8	14	15
 FATBB3B7	16	15
 FATBB4B6	11	15
 FATBB5	11	15
-FBXPA0	13	16			; revenant explosion
-FBXPB0	17	24
-FBXPC0	18	27
+FBXPA0	19	26			; revenant explosion
+FBXPB0	17	27
+FBXPC0	17	32
 SSWVA1   18 61
 SSWVA2A8 15 64
 SSWVA3A7 11 66
@@ -1984,12 +1984,12 @@ SKULE8E2        16      33
 SKULE7E3        16      35
 SKULE6E4        18      32
 SKULE5  17      32
-SKULF0	14	32
-SKULG0	15	32
-SKULH0	13	33
-SKULI0	15	36
-SKULJ0	20	38
-SKULK0	24	42
+SKULF0	19	39
+SKULG0	16	38
+SKULH0	20	37
+SKULI0	24	40
+SKULJ0	27	42
+SKULK0	30	46
 SPIDA1	128	100		; spider mastermind
 SPIDA2	128	100
 SPIDA3	128	100