Enable running java perf via Makefile Fix #6317

Dependencies: 

1. Oracle Java 1.7
2. Maven (`brew install maven` on OSX)
3. Set JAVA_HOME (``export JAVA_HOME=`/usr/libexec/java_home` `` on OSX)

I haven't enabled adding the results to the table yet. Is everyone happy for me to do so? On my laptop, the results are: 

					Java
    				1.7.0_45
    fib				0.44
    parse_int		6.42
    quicksort		2.12
    mandel			0.31
    pi_sum			1.02
    rand_mat_stat	4.38
    rand_mat_mul	2.45