Fix for (Bug #2789)

Add MatlabFormatter for matlab style output.
See http://code.opencv.org/issues/2789
Merge branch 'master' into matlab_formatter
cv::findContours: Check if type of output data structure is right to store contours (vector<vector<Point>>).
Fixed scanning bug identified in comments in pull request #1119.
NFA calculations now generate better line segments.
Issue #3709 - PyBindings for LSD

Corrected crashing in Python bindings while using LSD_REFINE_NONE flags
Corrected not drawing lines in drawSegments and compareSegments in Python bindings
Removed "CV_" prefix from constants in docs

The `calib3d.hpp` has a definition of the constant that does not contain the prefix "CV_".
The affected methods were `findHomography` and `findEssentialMat`.
Now the documentation updates the definition of the constants to conform to the header.
Merge pull request #2824 from abidrahmank:pylsd
Merge pull request #2858 from 23pointsNorth:patch-3
Merge pull request #2774 from 23pointsNorth:lsd-nfa-fix
Merge pull request #2672 from a-wi:findContours
Merge pull request #2626 from KayKwon:matlab_formatter