rename src to pylib and in data.seq float rounding uses start as well

tests/test_geometry.py

@@ -14,7 +14,7 @@ import os
 import sys
 import math
 from numpy import allclose
-sys.path.insert(0, os.path.abspath('../src'))
+sys.path.insert(0, os.path.abspath('../pylib'))
 from data import fold_list
 from geometry import translate_xy, rotate_xy, interpolate_hermite, lines, cubics
 from geometry_plot import plot_lines, plot_cubic_lines