`Calculate attendance` page.

[HarshKapadia2]

• Refer to issues #17 for pdf criteria #6 getting students as per attendance percentage.

[HarshKapadia2]

• Get attendance as per entered date range.

• Three options:

  • Get only as per attendance criteria (No date range provided, so default range: From beginning of sem to end of sem.)
  • Get only as per date range (no tick or cross as no attendance criteria provided)
  • Get as per both date range and criteria.

[HarshKapadia2]

Handle edge case - One subject having multiple teachers:

In those teacher's class' calculate attendance page, add an option to:

• Calculate their own lecture's attendance.
• Calculate a combined attendance of all the teachers taking that subject in that class.

PS: Provide the same three options as the above reply for each of these two options.