Preliminary wild data enhancements

Still need to fix the Headbutt trees and fishing groups, but this is a great start.

At a glance:
- Houndour and Slugma are now in the Burned Tower. Magby is also now featured as well as Magmar.
- Ilex Forest now uses mostly Johto Pokemon, including Yanma, Ledyba, and Spinarak.
- Larvitar is now in Mt. Mortar, and Marill is now an all-day encounter.
- Sneasel is now an all-day encounter in the Ice Path.
- Misdreavus replaces Gastly outside of Sprout Tower at night. That's Routes 31, 32, and 36.
- Murkrow is now a 10% encounter on all the routes near Ecruteak City. That's Routes 38, 42, and 37.
- Route 38 also has the all-day Snubbull encounters from GS, and uses Silver's data to have a Meowth-Moibelle dichotomy later.
- Route 42 also uses Gold's wild data, featuring Mankey, Flaaffy, and Girafarig. With Murkrow at night, this route is now very Johto-y.
- Route 43 also has Gold's Flaaffy and Girafarig, but keeps the presence of Furret from Crystal.
- Viridian Forest now has wild data built from Ilex Forest.

Markers for unimplemented Pokemon to be used have also been added. Buu as a nighttime Jynx replacement, etc.

data/wild/kanto_grass.asm

@@ -869,5 +869,35 @@ KantoGrassWildMons:
 	dbw 43, MAROWAK
 	dbw 43, CHANSEY
 	end_grass_wildmons
+
+; Viridian Forest uses Ilex Forest's data for now.
+; Yes, it was THAT bad.
+	def_grass_wildmons VIRIDIAN_FOREST
+	db 4 percent, 4 percent, 4 percent ; encounter rates: morn/day/nite
+	; morn
+	dbw 5, CATERPIE
+	dbw 6, METAPOD
+	dbw 6, CATERPIE
+	dbw 5, PARAS
+	dbw 5, ZUBAT ; KOKANA
+	dbw 6, PARAS
+	dbw 6, PIKACHU
+	; day
+	dbw 5, CATERPIE
+	dbw 6, CATERPIE
+	dbw 5, METAPOD
+	dbw 6, METAPOD
+	dbw 5, ZUBAT ; KOKANA
+	dbw 6, PARAS
+	dbw 6, PIKACHU
+	; nite
+	dbw 5, ODDISH ; KOTORA
+	dbw 6, ODDISH ; KOTORA
+	dbw 6, ZUBAT
+	dbw 5, PARAS
+	dbw 5, ZUBAT ; KOKANA
+	dbw 6, PARAS
+	dbw 6, PIKACHU
+	end_grass_wildmons
 	
 	db -1 ; end