Fixed StandardTypeLocator to only know about java.lang.* out of the box. Doc fixes related to that.

org.springframework.expression/src/main/java/org/springframework/expression/spel/support/StandardTypeComparator.java

@@ -65,7 +65,6 @@ public class StandardTypeComparator implements TypeComparator {
 			return ((Comparable) left).compareTo(right);
 		}
 		
-		// How do we get to this line...?
 		throw new SpelException(SpelMessages.NOT_COMPARABLE, left.getClass(), right.getClass());
 	}
 

org.springframework.expression/src/main/java/org/springframework/expression/spel/support/StandardTypeLocator.java

@@ -47,8 +47,8 @@ public class StandardTypeLocator implements TypeLocator {
 
 	public StandardTypeLocator(ClassLoader loader) {
 		this.loader = loader;
+		// Similar to when writing Java, it only knows about java.lang by default
 		registerImport("java.lang");
-		registerImport("java.util");
 	}
 
 
@@ -95,5 +95,9 @@ public class StandardTypeLocator implements TypeLocator {
 	public List<String> getImportPrefixes() {
 		return Collections.unmodifiableList(this.knownPackagePrefixes);
 	}
+	
+	public void removeImport(String prefix) {
+		this.knownPackagePrefixes.remove(prefix);		
+	}
 
 }