findCorners from lines Successfully tested with real data. Grid2D successfully tested with real data

First version of corner detection. Builds ok, tested with real data , but too many corners appera... still debugging

Improved performance of Hough line fineder by a actor of 2.5. Sparse matrix filled through Triplet's.

Tested version of LaserScan, ScanSegment and LineSegment. Still missing merging at ScanSegment level to join close segments. Not convinced on jumping criteria applieda at LaserScan::ranges2xy()

Hough Line extraction debugged and checked with TNO rosbag. It remains to modify entry type of laser points

changed typedefs of Eigen::Matrix to Rowmajor. TODO: change name, it collides with same wolf typedefs