Add license clarification.

libjava/ChangeLog

libjava/LIBGCJ_LICENSE

libjava/gnu/classpath/Configuration.java.in

libjava/gnu/gcj/runtime/StringBuffer.java

libjava/gnu/java/awt/BitMaskExtent.java

libjava/gnu/java/awt/Buffers.java

libjava/gnu/java/awt/ComponentDataBlitOp.java

libjava/gnu/java/awt/GLightweightPeer.java

libjava/gnu/java/beans/BeanInfoEmbryo.java

libjava/gnu/java/beans/EmptyBeanInfo.java

libjava/gnu/java/beans/ExplicitBeanInfo.java

libjava/gnu/java/beans/IntrospectionIncubator.java

libjava/gnu/java/beans/editors/ColorEditor.java

libjava/gnu/java/beans/editors/FontEditor.java

libjava/gnu/java/beans/editors/NativeBooleanEditor.java

libjava/gnu/java/beans/editors/NativeByteEditor.java

libjava/gnu/java/beans/editors/NativeDoubleEditor.java

libjava/gnu/java/beans/editors/NativeFloatEditor.java

libjava/gnu/java/beans/editors/NativeIntEditor.java

libjava/gnu/java/beans/editors/NativeLongEditor.java