Set-theoretic types: representation of all data types

[josevalim]

The goal is to represent all data types within types:

• [x] Non-divisible types (integer, floats, pids, etc)
• [x] Dynamic
• [x] Atoms
• [x] Maps
  • [ ] New representation which is more efficient for negations
  • [ ] Domain key-types
  • [x] map_fetch
  • [x] map_put
  • [x] map_delete
  • [ ] map_keys
  • [ ] map_values
  • [ ] Map module
• [x] Tuples
  • [ ] Generalize :open / :closed
  • [x] tuple_fetch
  • [x] tuple_insert
  • [x] tuple_delete
  • [x] tuple_values
• [x] Lists
  • [x] list_hd
  • [x] list_tl
• [x] Functions
  • [x] apply/2 and fun.(args...)
  • [x] fn ... -> ... end (expr)
  • [x] Strong capture (expr)
  • [x] Inferred capture (expr)
  • [x] Unions of closures / empty applications
  • [x] Pretty printing

See #14558 and #13881.