rob-murray/os-leaflet — pull request #5 by jhrrsn (2014-03-07 13:12:28+00:00)
Title: Replaced OSGB36 +datum with +towgs84 parameter to proj4 string

This seems to further improve on Bug #2. Something in the proj4 OSGB36 datum is miscalculating coordinate conversions, and using this alternative definition seems to move points to the correct location with my test cases.