This simple detector runs up to two times faster than LSD while achieving
competitive results. Please evaluate the algorithm with samples/fld_lines.cpp

note that reference was merely regenerated, not verified.

caffe/vision_layers.hpp is gone. also fix some warnings.

added thinning sample
added thinning tests

- added area under "lost track ratio" curve statistics
- added "lost track ratio" curve plot
- minor fixes

- used C++ to handle resources and output
- simplified and refactored the code
- changed statistic calculation (precision, recall, etc)
- used CommandLineParser -> CL interface has changed

added error msg for samples