Added a 'special' test for benchmarking

It prints out the mean and standard deviation for tag detection
on ~100 runs.
Remove marker unwrapping

Instead, project sampling points directly in the
original image.

Execution time divided by ~3
Updated 'Refine' to be run at the image level

Instead of the Quad level. This allow to run Refine before decoding
markers. This is especially useful with the new version of
ReadBits that project samples points into the image: precise
localization of the markers enhance the decoding accuracy.
Prevent exception when refining distored quads corners
Added more images to integration test
Make sure the 'objects' samples compiles with opencv3
Added a sample app that outputs on stdout the list of markers in an image
Eliminate the tag 682 from recognition

Tag 682 is a fully black marker. It can be quite easily falsely detected in dark zones.
Updated the expected test results
Removed dead code formerly used by ReadBits
Readbits binarises only the sample points

The speed gain is just micro-optimisation, but the detection is increased
a lot, because OTSU finds a threshold to classify only the sampled pixels
rather than the whole tag image.

Readbits was also improved by computing the sampling positions directly from
the corners of the tag rather than an estimation of the corners of the data
matrix.
Lowered the limit on the size of found quads

Also fixed an exception happening in ReadBits when the corner of a tag is
ouside of the image (Refine can produce such corners)
More feedback on which tag fails the tests

Extracted the metadata about the test images (i.e. filename and which tags are
present on the image) into a separate file.
Added the list of tags that are known to be undetected, in order to easily get
a feedback on which ones are new false negatives, and which ones are new true
positives.
Support LSD to detect quads

Use the LineSegmentDetector [1] algorithm instead of Canny+FindContours
to detect quads in the image.

The process is about x2 slower, but it significantly improves detection
rates.

The LSD algorithm replace Canny+FindContours when the compilation flag
EXPERIMENTAL_LSD is ON.

[1]
http://docs.opencv.org/trunk/modules/imgproc/doc/feature_detection.html#linesegmentdetector