correct minimum and maximum mark conversion

Signed-off-by: semteacher <semteacher@gmail.com>
repaint table row colors due to different eduplan id

Signed-off-by: semteacher <semteacher@gmail.com>
Merge pull request #4 from semteacher/grade_system-12

Grade system 12 improvement
Merge branch 'grade_system-12'
Merge branch 'master' of git://github.com/MILLKA3000/tdmu-suite
Merge branch 'master' into listng_directory-file_calck
continue experiments

Signed-off-by: semteacher <semteacher@gmail.com>