Fixed a bug where params.PFmode = true caused incorrect edge detection results.
Updated edge_drawing.py to support the new EDColor feature.
Created a new edge_drawing_demo.cpp for demonstrating the EDColor feature.
Updated ximgproc.bib to include references for EDColor.
Added tests for PFmode and EDColor in test_fld.cpp.
Added CV_WRAP to Params::read and Params::write functions to expose them to Python bindings.
the class NFALUT uses the code from original ED code
