Verify data table sizes with table_width and assert_table_length macros

This was discussed in #706

It also uncovered some off-by-one issues with defining some constants.

A few structs now use rsreset/_RS to define their offset constants, as discussed in #739

audio/cry_pointers.asm

@@ -1,4 +1,6 @@
 Cries:
+; entries correspond to CRY_* constants (see constants/cry_constants.asm)
+	table_width 3, Cries
 	dba Cry_Nidoran_M
 	dba Cry_Nidoran_F
 	dba Cry_Slowpoke
@@ -67,3 +69,4 @@ Cries:
 	dba Cry_Aipom
 	dba Cry_Dunsparce
 	dba Cry_Donphan
+	assert_table_length NUM_CRIES

audio/music_pointers.asm

@@ -2,6 +2,7 @@
 
 Music:
 ; entries correspond to MUSIC_* constants
+	table_width 3, Music
 	dba Music_Nothing
 	dba Music_TitleScreen
 	dba Music_Route1
@@ -106,3 +107,4 @@ Music:
 	dba Music_SuicuneBattle
 	dba Music_BattleTowerLobby
 	dba Music_MobileCenter
+	assert_table_length NUM_MUSIC_SONGS

audio/sfx_pointers.asm

@@ -1,5 +1,6 @@
 SFX:
 ; entries correspond to SFX_* constants
+	table_width 3, SFX
 	dba Sfx_DexFanfare5079
 	dba Sfx_Item
 	dba Sfx_CaughtMon
@@ -208,3 +209,4 @@ SFX:
 	dba Sfx_TwoPcBeeps
 	dba Sfx_4NoteDitty
 	dba Sfx_Twinkle
+	assert_table_length NUM_SFX