Speedup function pathClone() by using Array.slice() instead of clone()

Example: chinese character evolution
before speedup: http://www.tudou.com/programs/view/PmQB_0NAfog/
after speedup:  http://www.tudou.com/programs/view/fZmvka4f59Q/
Speedup R.parsePathString() function

Using String.split() to make params from string to array.
Merge improvement of ParsePath
Add modify description and demo.