modified highgui and ts modules and cmakelists for ios cross-compiling, added ios toolchains, added ios build tutorial

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 the "How to write a tutorial for OpenCV?" tutorial. Made some corrections to the feature2D TOC tree. Small visual improvements for the video-write.rst file. Deleted a definition file that served no purpose.

Added reference to Nvidia TADP into Android tutorial; refactored both Android tutorials; fixed some rst warnings

Added the tutorial "Using OpenCV Android binary package to compile applications, which use OpenCV from native level".

Sample files for image scanning, basic Mat, file I/O. Added Victors removed tutorials back in the system. Some typo fixing.Expanded conf.py with new global links.

Ok, now optimized the tutorial size for real. Made JPG/PNG optimization for all the images. Modified some tutorial files to follow these size optimizations. Now the tutorial PDF generated is 3.95MB, so enjoy!

2) Added a raw Latex page break directive after each TOC tree. (For the PDF tutorial look).
3) Two finished tutorials: 
   a) one describing how the Mat data structure works and its output capabilities (format function) (demonstration YouTube video included).
   b) one describing image scanning operations plus the LUT function (demonstration YouTube video included). 
   c) a basic filtering approach (plus multi row image scanning demonstration) in the work.

Added the OpenCV with Visual Studio tutorial. Enhanced, extended the Windows Installation one. Some minor CSS changes to avoid unnecessary large spaces inside enumerations in the tutorials. 

Reformatted the TOC tables in tutorials to look just as good in PDFs as in HTML. Updated the default.css_t too for this. Added the "Windows Install" tutorial (with videos). 

Some reST syntax correction. Now the PDF documentation builds correctly under Windows using MIKTEX. Some update on the tutorial structure. Some CSS syntax correction. Windows Install Tutorial v0.4. 

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