added some files from content.open-ra.org, fixes #2182

adds Volkov with some minor changes (no C4, range fixes)
adds soviet forward command center build animation
adds icon for mines (not visible in-game yet)

mods/ra/sequences.yaml

@@ -3,8 +3,10 @@ fcom:
 		Start: 0
 	damaged-idle:
 		Start: 1
-	make:
+	make: fcommake
 		Start: 0
+		Length: *
+
 oilb:
 	idle:
 		Start: 0
@@ -2122,3 +2124,53 @@ overlay:
 	target-invalid:
 		Start: 1
 
+e8:
+	stand:
+		Start: 0
+		Facings: 8	
+	run:
+		Start: 8
+		Length: 5
+		Facings: 8
+	shoot:
+		Start: 56
+		Length: 4
+		Facings: 8
+	prone-stand:
+		Start: 88
+		Length: 2
+		Facings: 8
+	prone-run:
+		Start: 104
+		Length: 4
+		Facings: 8
+	standup-0:
+		Start: 136
+		Length: 2
+		Facings: 8
+	prone-shoot:
+		Start: 152
+		Length: 4
+		Facings: 8
+	idle1:
+		Start: 184
+		Length: 26
+		Tick: 120
+	die1:
+		Start: 210
+		Length: 8
+	die2:
+		Start: 218
+		Length: 8
+	die3:
+		Start: 226
+		Length: 8
+	die4:
+		Start: 234
+		Length: 12
+	die5:
+		Start: 246
+		Length: 18
+	die6: electro
+		Start: 0
+		Length: *