Fix some ranged units where image_diagonal= wasn't specified.

This lead to the 'too fast for the eye to see' ranged effect :) I
might have missed some.

data/units/Cave_Spider.cfg

@@ -31,6 +31,7 @@ get_hit_sound=hiss.wav
 		begin=-200
 		end=0
 		image=projectiles/web.png
+		image_diagonal=projectiles/web.png
 		[/missile_frame]
 	range=long
 	damage=8

data/units/Elvish_Druid.cfg

@@ -55,6 +55,7 @@ get_hit_sound=female-hit.wav
 		begin=-200
 		end=0
 		image=projectiles/entangle.png
+		image_diagonal=projectiles/entangle.png
 		[/missile_frame]
 	[/attack]
 
@@ -74,6 +75,7 @@ get_hit_sound=female-hit.wav
 		begin=-200
 		end=0
 		image=projectiles/thorns.png
+		image_diagonal=projectiles/thorns-ne.png
 		[/missile_frame]
 	[/attack]
 [/unit]

data/units/Elvish_Shyde.cfg

@@ -63,6 +63,7 @@ get_hit_sound=female-hit.wav
 		begin=-150
 		end=0
 		image=projectiles/entangle.png
+		image_diagonal=projectiles/entangle.png
 		[/missile_frame]
 	[/attack]
 
@@ -82,6 +83,7 @@ get_hit_sound=female-hit.wav
 		begin=-200
 		end=0
 		image=projectiles/thorns.png
+		image_diagonal=projectiles/thorns-ne.png
 		[/missile_frame]
 	[/attack]
 [/unit]

data/units/Goblin_Pillager.cfg

@@ -48,6 +48,7 @@ get_hit_sound=wolf-cry.wav
 		begin=-200
 		end=0
 		image=projectiles/web.png
+		image_diagonal=projectiles/web.png
 		[/missile_frame]
 		[sound]
 		time=-100