Found via `codespell -q 3 --skip="./3rdparty" -I ../opencv-whitelist.txt`

Remove useless backslash.

corrected constants,  changed objdetection.cpp as well

updated objDetection2.cpp as well

fixed headers in objdetection2.cpp

removed useles RNG

fixed buildbot warnings (wow, i like that bot!)

victim of the war on whitespace

fixing buildbot warnings

fixing last buildbot warning, heya .

trying to rebase/squash commits

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

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

updated links in cheatsheet
renamed directory for Mat tutorial 
changed links from willow docs to opencv.itseez.com, from Trac to current Redmine

Added the "Camera calibration With OpenCV" tutorial. Extended with a few global links the conf.py file. Corrected an error in the linux_install.rst and one in the cascade_classifier.rst file. 

New structure (following the documentation) for the tutorials. Normalized image sizes for TOC display.