If we have perfect matches (min_dist == 0.0), then strict comparison
fails. Making it non-strict results in treating perfect matches as
good.

These codes should be included into regular builds.

Changes made for OpenCV 2.4.2 compatibility

error in the tutorial Similarity check (PNSR and SSIM) on the GPU

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. 

Added to the tutorials the "Support Vector Machines for Non-Linearly Separable Data" contributed by Fernando Iglesias García. Corrected a mistake in the gpu-basics-similarity.rst file. 

Added the "Similarity check (PNSR and SSIM) on the GPU" tutorial. Corrected an highgui TOC tree mistake.

Added the How to create videos with OpenCV Tutorial. Made some corrections to the feature2d, to get rid of some documentation build errors. 

Added tutorial for features2d using homography to find a planar object (Based on the well known find_obj.cpp

Added the "Mask operations on matrices" tutorial (with its sample). Plus modified some other core tutorials.

Added Fernandos first tutorial regarding SVMs. Extended the global links (conf.py). Corrected the author names. Minor modification to the dft tutorial.