title: Get subpath in Raphael.js between two points, not positions
body: <p>I have a path in Raphael.js which is a bezier curve.  Two lines intersect this path.  I can get the points of the intersections with <code>Raphael.pathIntersection()</code>.  I want to get the path string for the subpath between these two points, though.  Raphael.getSubPath() needs to know the positions along the path, but I don't know these positions, just the absolute points.  How can I go about getting the positions of these intersections so I can find the subpath?</p>
  
  <p>Thanks</p>
  
  <p>Edit: below is the intersection object that is returned for the first of the two intersections that make up the start and finish of the subpath I want to find.  I can see from this which segment the intersection occurs in, but how to get the actual position along the path from its start from this information?</p>
  
  <pre><code>0: Object
    bez1: Array[8]
      0: 746.6695658365885
      1: 444.9913024902344
      2: 746.6695658365885
      3: 444.9913024902344
      4: 767.3333333333334
      5: 383
      6: 767.3333333333334
      7: 383
    bez2: Array[8]
      0: 743
      1: 427
      2: 750
      3: 428.5
      4: 752.5
      5: 428.8333333333333
      6: 761
      7: 432
    segment1: 1
    segment2: 9
    t1: 0.330626006717131
    t2: 0.5304347826090153
    x: 751.9768115942079
    y: 429.0695652173915
  </code></pre>