TODO: Round Robin separation for datanodes
Merge branch 'pa3' of https://github.com/shaunhaow/OS into pa3

Conflicts:
	pa3/build/datanode
	pa3/build/libdfscommon.a
	pa3/build/namenode
	pa3/client/dfs_client.c
	pa3/client/dfs_client.o
	pa3/common/dfs_common.o
	pa3/common/libdfscommon.a
	pa3/datanode/datanode
	pa3/datanode/dfs_datanode.o
	pa3/dfs
	pa3/local_file_1
	pa3/local_file_large_1
	pa3/local_file_medium_1
	pa3/namenode/dfs_namenode.o
	pa3/namenode/namenode
	pa3/test.o