BufferedWriter and BufferedReader

        Changes to be committed:
	new file:   javaBiBasic/src/javaBiBasic/Day19/BufferedReaderTest.java
	new file:   javaBiBasic/src/javaBiBasic/Day19/BufferedWriterDemo.java
        Changes not staged for commit:
	modified:   demo.txt#	modified:   demo_copy.txt
	deleted:    javaBiBasic/src/javaBiBasic/Day19/IoBufferWriter.java