Rename "feet and head follow" commands

The lot of these were rather misnamed, since they're used to replace
part of the player or enemy with objects for several background effects.
https://github.com/pret/pokecrystal/pull/578#issuecomment-440996244

engine/battle_anims/anim_commands.asm

@@ -334,8 +334,8 @@ BattleAnimCommands::
 	dw BattleAnimCmd_IncObj
 	dw BattleAnimCmd_SetObj
 	dw BattleAnimCmd_IncBGEffect
-	dw BattleAnimCmd_EnemyFeetObj
-	dw BattleAnimCmd_PlayerHeadObj
+	dw BattleAnimCmd_BattlerGFX_1Row
+	dw BattleAnimCmd_BattlerGFX_2Row
 	dw BattleAnimCmd_CheckPokeball
 	dw BattleAnimCmd_Transform
 	dw BattleAnimCmd_RaiseSub
@@ -681,7 +681,7 @@ endr
 	ld de, vTiles0 tile BATTLEANIM_BASE_TILE
 	add hl, de
 	ld a, [wBattleAnimByte]
-	call LoadBattleAnimObj
+	call LoadBattleAnimGFX
 	ld a, [wBattleAnimTemp0]
 	add c
 	ld [wBattleAnimTemp0], a
@@ -767,7 +767,7 @@ BattleAnimCmd_SetObj:
 	ld [hl], a
 	ret
 
-BattleAnimCmd_EnemyFeetObj:
+BattleAnimCmd_BattlerGFX_1Row:
 	ld hl, wBattleAnimTileDict
 .loop
 	ld a, [hl]
@@ -778,11 +778,11 @@ BattleAnimCmd_EnemyFeetObj:
 	jr .loop
 
 .okay
-	ld a, ANIM_GFX_PLAYER
+	ld a, ANIM_GFX_PLAYERHEAD
 	ld [hli], a
 	ld a, ($80 - 6 - 7) - BATTLEANIM_BASE_TILE
 	ld [hli], a
-	ld a, ANIM_GFX_ENEMY
+	ld a, ANIM_GFX_ENEMYFEET
 	ld [hli], a
 	ld a, ($80 - 6) - BATTLEANIM_BASE_TILE
 	ld [hl], a
@@ -821,7 +821,7 @@ BattleAnimCmd_EnemyFeetObj:
 	jr nz, .LoadFeet
 	ret
 
-BattleAnimCmd_PlayerHeadObj:
+BattleAnimCmd_BattlerGFX_2Row:
 	ld hl, wBattleAnimTileDict
 .loop
 	ld a, [hl]
@@ -832,11 +832,11 @@ BattleAnimCmd_PlayerHeadObj:
 	jr .loop
 
 .okay
-	ld a, ANIM_GFX_PLAYER
+	ld a, ANIM_GFX_PLAYERHEAD
 	ld [hli], a
 	ld a, ($80 - 6 * 2 - 7 * 2) - BATTLEANIM_BASE_TILE
 	ld [hli], a
-	ld a, ANIM_GFX_ENEMY
+	ld a, ANIM_GFX_ENEMYFEET
 	ld [hli], a
 	ld a, ($80 - 6 * 2) - BATTLEANIM_BASE_TILE
 	ld [hl], a