Fixed the sample.
The accurate LineSegmentDetector object.
trajectory widget with frustums
plane widget size fix
shorten Trajectory widget implementation
remove unnecessary declaration
overlay image widget constructor with Rect
Merge remote-tracking branch 'origin/2.4' into merge-2.4

Conflicts:
	modules/core/include/opencv2/core/types_c.h
	modules/gpu/src/cuda/imgproc.cu
	modules/gpu/src/cuda/safe_call.hpp
	modules/gpu/src/error.cpp
	modules/gpu/src/imgproc.cpp
	modules/imgproc/src/distransform.cpp
	modules/imgproc/src/shapedescr.cpp
	modules/python/src2/cv2.cpp
	modules/python/src2/cv2.cv.hpp
image 3d widget use texture instead of imageactor for more flexibility (such as resizing)
Drop the legacy CMake options.

3.0 seems like an appropriate time to do that.
image 3d widget with position, normal, up_vector
using explicit keyword in the ERStat constructor for safe contruction
using Rect for storing the bounding box instead of an integer array
removed extra cv:: scope qualifiers for better readability
removed some unnecessary ERStat members as they are easily computable from others
intial implementation of frustum + image (the color of the frustum is currently dependent on the first pixel of the image)
add const keywords to gridwidget constructor
Gridwidget with plane coefficients
GridImpl structure to shorten grid widget implementation
move image copying structure to viz3d_impl: ConvertToVtkImage