Added script conn_mat_circle.py

Usage examples (for STUT_MRI_Paper_1):
      ipython --pylab

      run conn_mat_circle.py analyze_pt2_seedOnly_cmat_ds.speech.lh.mat lh PFS --vmax 305.7
      run conn_mat_circle.py analyze_pt2_seedOnly_cmat_ds.speech.lh.mat lh PWS --vmax 305.7