case-sensitivity for some languages

plugins/groovy/src/org/jetbrains/plugins/groovy/GroovyLanguage.java

@@ -28,5 +28,9 @@ public class GroovyLanguage extends Language {
   public GroovyLanguage() {
     super("Groovy");
   }
-  
+
+  @Override
+  public boolean isCaseSensitive() {
+    return true;
+  }
 }

xml/impl/src/com/intellij/lang/xml/XMLLanguage.java

@@ -94,6 +94,12 @@ public class XMLLanguage extends CompositeLanguage {
     super(name, mime);
   }
 
+  @Override
+  public boolean isCaseSensitive() {
+    return true;
+  }
+
+
   public XmlPsiPolicy getPsiPolicy() {
     return CDATA_ON_ANY_ENCODED_POLICY;
   }