2-size array fix

The code wasn't applying the 2-size array shortcut mini-optimisation before due to a missing return, now fixed.

Extreme values and infinities sorting

Changes:

• tr-sort can now sort data containing extreme values and infinities correctly

Partially optimised

Reintroduced some partial small-array optimisation

Initial working version

The code in this version is exactly the same as the original prototype, except without the small array size optimisation part, which doesn't work currently.