Type coercion for luajava package, make luajava an "addon"

src/main/java/lua/value/LString.java

@@ -6,17 +6,23 @@ import lua.StackState;
 public class LString extends LValue {
 
 	final String m_string;
+	final int m_hash;
 	
 	public LString(String string) {
 		this.m_string = string;
+		this.m_hash = string.hashCode();
 	}
 
 	public boolean equals(Object o) {
-		return o != null && o instanceof LString && m_string.equals(((LString)o).m_string);
+		if ( o != null && o instanceof LString ) {
+			LString s = (LString) o;
+			return m_hash == s.m_hash && m_string.equals(s.m_string);
+		}
+		return false;
 	}
 
 	public int hashCode() {
-		return m_string.hashCode();
+		return m_hash;
 	}
 
 	// TODO: what to do with LuaState?