Fix some usability issues with age names.

Disallow exporting from the World panel if the age name is blank and
draw attention to it in the UI.

korman/properties/prop_world.py

@@ -193,7 +193,6 @@ class PlasmaAge(bpy.types.PropertyGroup):
                                     default=True)
     age_name = StringProperty(name="Age Name",
                               description="Name of the Age to be used for data files",
-                              default="Korman Age",
                               options=set())
 
     # Implementation details

korman/ui/ui_world.py

@@ -60,7 +60,9 @@ class PlasmaGamePanel(AgeButtonsPanel, bpy.types.Panel):
             op = row.operator("world.plasma_game_add", icon="FILE_FOLDER", text="Change Path")
             op.filepath = active_game.path
             op.game_index = active_game_index
+            row = row.row(align=True)
             row.operator_context = "EXEC_DEFAULT"
+            row.enabled = bool(age.age_name.strip())
             op = row.operator("export.plasma_age", icon="EXPORT")
             op.filepath = str((Path(active_game.path) / "dat" / age.age_name).with_suffix(".age"))
 
@@ -121,6 +123,7 @@ class PlasmaAgePanel(AgeButtonsPanel, bpy.types.Panel):
         col = split.column()
         col.label("Age Settings:")
         col.prop(age, "seq_prefix", text="ID")
+        col.alert = not age.age_name.strip()
         col.prop(age, "age_name", text="")
 
         layout.separator()