Fixed gp.eig().

ntpl.gulp.eig() was returning the eigenvectors in the wrong format. Now switched
to correct format. Correct format is columns are the modes and rows are the
different atoms in the unit cell in different directions. E.g. columns:
mode1, mode2, mode3, etx. rows: 1x, 1y, 1z, 2x, 2y, 2z, etc.