29 mar: Added radiation shielding problems.
16 mar: Minor backend revisions.
7 mar: Implemented JQuery for subject selection and PHP response. Thanks for the tip Paul.
3 mar: Randomised problems after test selection and added inverse square law problems.
2 mar: Added radioactive decay problems.
27 feb: Basic calculation implementation for wavelength and some fighting the layout.
Wavelength problems are functional. Progress thus far: Basic but functional.
26 feb: Basic subject selection functionality.