add image tuning: 50% resize and 90 degree rotation.
modified: grab.cpp: add tuning for specific experiment.
modified: grab.help.output: auto-updated.
todo and comments
modified:   grab.cpp: todo cut, zoom; comment static part of the code: rotate and zoom.
modified:   grab.help.output
add next todos
modified:   grab.h: todo implement Ximea and V4L grab classes.