Implicit type arguments, bulleted type tuples, multiple items in indented tuples

[edemaine]

This started as an implementation of the idea that A B in a type context should parse as A<B>. But along the way I noticed that type tuples were woefully lacking compared to array literals.

• Generally revamp type tuple parser to match array literal parser, in particular:
  • Support multiple types on one line of an indented tuple
  • Support bulleted type tuples
• Support implicit type arguments, with space or indentation, similar to function calls

TODO: Documentation

[STRd6]

Looks good, just double check that the pop mutation in those 4 places is safe.

Thanks!