Cleanups
Use primed operators: `+'`, `*'`, `-'`, `inc'` and `dec'`
2.5
2.6
Fix annotation of `clojure.lang.Numbers/minusP`
2.7, 2.8 and 2.10 (2.9 is self-evident)
2.11
2.12
Use `fn>` if possible
2.13, 2.14 and 2.15 (2.16 is skipped)
2.17
2.18
Fix refer
Use `Coll` instead of `Seqable`
Add `reverse_'`
2.19
Add `^:non-check`
2.20
Fix
Add `last_`