Remove or fix some broken art files. Bring wrld_med_plant.png back from the dead.

Based on patch by stanislas69, refs #2524
Fixes #3796

This was SVN commit r18718.

binaries/data/mods/public/art/actors/flora/trees/grass_1.xml

@@ -1,17 +1,13 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
 <actor version="1">
-
   <castshadow/>
-
   <group>
     <variant frequency="100" name="Base">
       <animations/>
       <mesh>gaia/wrld_grass_1.dae</mesh>
       <props/>
-      <textures><texture file="gaia/wrld_med_plant.dds" name="baseTex"/></textures>
+      <textures><texture file="gaia/wrld_med_plant.png" name="baseTex"/></textures>
     </variant>
   </group>
-
   <material>basic_trans_wind.xml</material>
-
 </actor>

binaries/data/mods/public/art/actors/props/units/heads/rome_helmet_b.xml

@@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
-<actor version="1">
-
-  <castshadow/>
-
-  <group>
-    <variant frequency="100" name="Base">
-      <mesh>temp/plac_helmet_e.dae</mesh>
-      <textures><texture file="props/helmet/hele_xenophon.dds" name="baseTex"/></textures>
-    </variant>
-  </group>
-
-</actor>

binaries/data/mods/public/art/actors/temp/hele_siege_operator.xml

@@ -6,7 +6,7 @@
   <group>
     <variant frequency="100" name="Base">
       <animations>
-        <animation file="biped/inf_jav_atk_a.psa" name="Idle" speed="20"/>
+        <animation file="infantry/javelin/attack/ijv_off_01.psa" name="Idle" speed="20"/>
         <animation file="biped/inf_spear_shield_atk_a.psa" name="Idle" speed="20"/>
       </animations>
       <mesh>skeletal/m_tunic_a.pmd</mesh>

binaries/data/mods/public/art/actors/units/persians/infantry_javelinist_a.xml

@@ -28,14 +28,9 @@
         <prop actor="props/units/weapons/jav_ammo.xml" attachpoint="l_hand"/>
         <prop actor="props/units/cape_hd.xml" attachpoint="shoulders"/>
       </props>
-    </variant>
-  </group>
-  <group>
-    <variant>
-      <textures><texture file="skeletal/pers_ijv_b_1.dds" name="baseTex"/></textures>
-    </variant>
-    <variant>
-      <textures><texture file="skeletal/pers_ijv_b_2.dds" name="baseTex"/></textures>
+      <textures>
+        <texture file="skeletal/pers_ijv_b_1.dds" name="baseTex"/>
+      </textures>
     </variant>
   </group>
   <group>

binaries/data/mods/public/art/actors/units/spartans/cavalry_spearman_e_r.xml

@@ -35,7 +35,6 @@
     <variant frequency="1" name="Armor 3">
       <textures>
         <texture file="skeletal/hele_isp_e_b.dds" name="baseTex"/>
-        <texture name=""/>
       </textures>
     </variant>
   </group>

binaries/data/mods/public/simulation/templates/special/actor.xml

@@ -16,7 +16,6 @@
     <Range>0</Range>
   </Vision>
   <VisualActor>
-    <Actor>(should be overridden)</Actor>
     <SilhouetteDisplay>false</SilhouetteDisplay>
     <SilhouetteOccluder>false</SilhouetteOccluder>
     <VisibleInAtlasOnly>false</VisibleInAtlasOnly>