InputArray is a reference, and references are always constant anyway. Making
it const even causes a GCC warning.

Update on the class to reflect the review. Split the class into virtual and implementation. change of name to LineSegmentDetector, using Input/Output-Arrays, general clean ups.

http://www.code.opencv.org/issues/2023

eg:

In [3]: box = ((10,10),(5,5),0)

In [4]: cv2.boxPoints(box)
Out[4]:
array([[  7.5,  12.5],
       [  7.5,   7.5],
       [ 12.5,   7.5],
       [ 12.5,  12.5]], dtype=float32)

e.g. <opencv2/core/core.hpp> become <opencv2/core.hpp>

Also renamed <opencv2/core/opengl_interop.hpp> to <opencv2/core/opengl.hpp>

Made all STL usages explicit to be able automatically find all usages of
particular class or function.

use a ltype parameter to determine result Label image type; export stats with differening types over different outputarrays

-Change input/output order from (out Labeled, in Image) -> (in Image, Out Labeled) and convert
to Input/OutputArrays in the process.

-Adopt OutputArray for statistics export so that the algorithm is "wrapper friendly" and not requiring a new struct in
language bindings at the expense of using doubles for everything and slowing statistics computation down..

adjust output type to return int32... it should at least be unsigned but this breaks python bindings;
remove non-8bit input type support, not worth the binary size

connectedComponents: peep-hole optimizations, mostly surrouding the fact that cv::Mat::at is expensive in a tight-loop -also added a "blobstats" version

This reverts commit 94b97b7a.

This reverts commit 4aaaef59.

Conflicts:
    modules/imgproc/include/opencv2/imgproc/types_c.h
    modules/legacy/include/opencv2/legacy/legacy.hpp

This partly reverts commit 6ca61827.