FileUtils

Added this class for easy access to file. for now all methods in this class are static. we should decide which class to keep private and which public. and also need some correction if i have miss something. we can also add some other functionality here....
ByteStreams.copy already provides this as well http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/io/ByteStreams.html#copy(java.io.InputStream,%20java.io.OutputStream)