* 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.

Fix issue #8280: "fastmath.h related compile errors with Embarcadero C++ Builder 10.1"

Fix bug in camera_calibration.cpp that the program tries to
parse input of type VIDEO_FILE as IMAGE_LIST which causes the
program to crash.

If-condition was always true (alpha = 0.5 is set in Line 19).
Now the user input is checked to be between 0 and 1.
This is correct in the tutorial code for OpenCV 2.4.

 - brush up the implementation

* fix typos.

* Fix typos.

* Fix typos.

* Fix typos.

* Fix typos.