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.