add filters to record page
ajax delele records
refactoring models
add help and feedback pages
 separate grading to jquery.grader
grading note and feedback panels
integrate play records to end
add private not column to grade
refractoring grade create and destroy
update record show page grading
update grading save
move playing buttons to the top
grading different sequences
extract subnav components
adjust grading page display
step by step playing
move to prev step if step passed