version of phtest for top targets.
1. use phtest_by_target.m to test each single target via phtest.
2. use phtest_res_stat.m to stat the result from func $phtest_by_target.m
3. use plot_phtest_res_stat.m to plot the $target_stat result of step 2.

4. add weighted std for phtest, change the option in func $phtest_restart.m
5. rename plot_target_source.m to plot_stat_target_source.m