Updating YouTube link for new video.
Query Changed, to get the right problems in "solve a custom problem"
Bug Fix 2403
Handling return value of getInitial using typeof returnvalue==="number"
in case of any checks using getInitial Function
Changes in documentation associated with changing
format of sessions table.
Code review for zero initial value fix:  use test
that initial value is a number.
Also, query in available_problems.php doesn't make sense:  reverted to
original.
Merge branch 'ritesh'
Send the model task to the solutions table.
Update the solutions table using the SQL query:
  UPDATE solutions SET solution_graph = SUBSTRING(solution_graph, 9, LENGTH(solution_graph)-9)
     WHERE solution_graph REGEXP '^{"task":';
Fixed the time interval and time steps check in description editor