* Update linux_install.markdown

Grammar improvements, fixed typos.

* Update tutorials.markdown

Improvements in grammar.

* Update table_of_content_calib3d.markdown

* Update camera_calibration_square_chess.markdown

Improvements in grammar. Added answer.

* Update tutorials.markdown

* Update erosion_dilatation.markdown

* Update table_of_content_imgproc.markdown

* Update warp_affine.markdown

* Update camera_calibration_square_chess.markdown

Removed extra space.

* Update gpu_basics_similarity.markdown

Grammatical improvements, fixed typos.

* Update trackbar.markdown

Improvement for better understanding.

    * correct the part about fixed aspect
    * improve formatting
    * add snippet markers to source
    * replace inline code by @snippet
  - do not run calibration twice when using a imageList
  - make output consistent in itself (CamelCase vs no_camel_case) as well as with old camera calibrate sample
  - respect write extrinsic/ points flags
  - set the aspectRatio value when specified
  - fix writing of calibration settings. also update grammar.
  - fix intendation and remove some size_t -> int casts by using size_t

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.