Summation based benchmark for calculators

[pier4r]

Thanks gilles! Super neat.

Would be really nice to have the results (if possible with common entry mode and then in an optimized form, if it exists) for:
- a 41 version
- 41 CL
- dm41
- dm42
- hp 42s
- 35s
- a 48 version
- 12C (recent)
- 15C
- 50g with hpgcc (but this may be highly time consuming and not really usable in all day operations)
- 71B
- 67
- 34S
- Nspire CX
- A ti 84 (if possible recent)
- Casio primz
- Casio classpad (if possible 300 and then newer versions)
- casio 991ex
- Some sharp EL graphing or PC
- Also Nspire lua would be interesting (I can do it on the nspire handheld, although a CX should be better) but actually it would be very similar to a hpgcc version on the 50g, very unlikely to be used in all day operations since lua is clumsy to use on the nspire for actual math results.