sprites: add Cascade's pickups (etc.). (#1059)

* sprites: add Cascade's pickups (etc.).

Incidental upgrades to a couple other sprites to better match this higher-contrast style.

Took the opportunity to fix the scaling on the missile projectile and give it longer, simpler-looking fins.

CREDITS

@@ -980,3 +980,7 @@ D: musics: d_dm25, d_dm30, d_dm32
 
 S: SuperDave938
 D: textures
+
+S: Cascade
+D: sprites
+

buildcfg.txt

@@ -2143,8 +2143,8 @@ MANFB8B2	35	16
 AMMOA0	8	16
 ARM1A0	18	28
 ARM1B0	18	28
-ARM2A0	18	26
-ARM2B0	18	26
+ARM2A0	18	24
+ARM2B0	18	24
 BAL1A0	8	11
 BAL1B0	8	11
 BAL1C0	17	21
@@ -2207,11 +2207,11 @@ MISFA0	-110 -99
 MISFB0	-110 -94
 MISFC0	-111 -96
 MISFD0	-115 -91
-MISLA1	7	11
-MISLA5	7	11
-MISLA6A4	18	11
-MISLA7A3	32	11
-MISLA8A2	18	11
+MISLA1	9	12
+MISLA5	9	12
+MISLA6A4	13	13
+MISLA7A3	22	13
+MISLA8A2	13	13
 MISLB0	39	42
 MISLC0	38	46
 MISLD0	45	47
@@ -2346,7 +2346,7 @@ PVISA0	14	13
 PVISB0	14	13
 RKEYA0	8	19
 RKEYB0	8	19
-ROCKA0	5	25
+ROCKA0	5	24
 SAWGA0	-176	-60
 SAWGB0	-176	-59
 SAWGC0	-156	-81