Remove some deprecated [sound] tags.

Teach wmllint to spot and warn of these.

Minor dialog tweaks for Liberty.

data/campaigns/Liberty/scenarios/06_The_Gray_Woods.cfg

@@ -250,7 +250,7 @@
         [/message]
         [message]
             description=Helicrom
-            message= _ "Wrong.  Necromancers become slaves to their lich masters and eventually lose their humanity.  We have found that practicing the dark arts is not as hazardous as it may seem.  The balance of light and dark is a mystical secret we hope to discover.  As such, we exist between both worlds, fitting into neither one."
+            message= _ "Wrong.  Necromancers become slaves to their lich masters and eventually lose their humanity.  We have proven that practicing the dark arts need not lead down that path to damnation.  We remain human, and seek the mystical secret of balance between the Ways of Light and Darkness.  We dance between both Ways, adhering to neither."
         [/message]
         [message]
             description=Baldras
@@ -258,7 +258,7 @@
         [/message]
         [message]
             description=Helicrom
-            message= _ "We don't.  You have sought US out.  But, I do know of your situation and am willing to help.  The throne of Wesnoth, under a King or Queen, is a cow we always like to prod, so to speak."
+            message= _ "We don't.  You have sought us out.  But, I do know of your situation and am willing to help.  Any weakening the Throne of Wesnoth, whether it be occupied by King or Queen, aids us."
         [/message]
         [message]
             description=Helicrom

data/campaigns/Liberty/units/Avatar.cfg

@@ -36,11 +36,8 @@
             begin=-150
             end=100
             image=fire-dragon-attack-bite1.png
+            sound=wolf-bite.ogg		# Used to be time=-150
         [/frame]
-        [sound]
-            time=-150
-            sound=wolf-bite.ogg
-        [/sound]
     [/attack]
     [attack]
         name=godlike powers
@@ -57,11 +54,8 @@
             image=fire-dragon-attack-breath.png
             halo=halo/mage-halo1.png,halo/mage-halo2.png,halo/mage-halo3.png,halo/mage-halo4.png
             halo_x,halo_y=14,-14
+            sound=fire.wav	# Used to be time=-200
         [/frame]
-        [sound]
-            time=-200
-            sound=fire.wav
-        [/sound]
         [missile_frame]
             begin=-100
             end=0

data/campaigns/Liberty/units/Death_Squire.cfg

@@ -37,10 +37,7 @@
             begin=-100
             end=100
             image=undead-deathsquire-attack.png
+            sound=sword-1.ogg	# Used to be time=-250
         [/frame]
-        [sound]
-            time=-250
-            sound=sword-1.ogg
-        [/sound]
     [/attack]
 [/unit]

data/tools/wmllint

@@ -453,7 +453,11 @@ def validate_stack(stack, filename, lineno):
     "Check the stack for deprecated WML syntax."
     if verbose >= 3:
         print '"%s", line %d: %s' % (filename, lineno+1, stack)
-    pass
+    if stack:
+        (tag, attributes) = tagstack[-1]
+        ancestors = map(lambda x: x[0], tagstack)
+        if tag == "sound" and "attack" in ancestors:
+            print '"%s", line %d: deprecated [sound] within [attack] tag' % (filename, lineno+1)
 
 def validate_on_pop(tagstack, closer, filename, lineno):
     "Validate the stack at the time a new close tag is seen."
@@ -465,7 +469,6 @@ def validate_on_pop(tagstack, closer, filename, lineno):
     # deserialize an empty unit.
     if closer == "side" and "type" not in attributes and ("no_leader" not in attributes or attributes["no_leader"] != "yes") and "multiplayer" not in ancestors:
         print '"%s", line %d: [side] without type attribute' % (filename, lineno)
-    pass
 
 # Syntax transformations