Repeating cards

[oveddan]

This changes the behavior to have the home page projects repeat if there are less than 40 projects shown, to prevent it show projects appearing in different orders.

Some code changes:

• Simplified passing filtered students down to children by just passing an array of IStudentSummary[] as it was before.
• Changed CardMatrix to just contain the student itself, to simplify the code and make lookup easier. Additionally CardToShow now just contains the student and not the student index.

[EonYang]

I had a similar idea, thanks for doing this! Looks good. let merge it.