Multi-line string syntax

[cgay]

Implement multi-line strings as described in https://opendylan.org/proposals/dep-0008.html This is a work in progress: https://github.com/dylan-lang/opendylan/pull/808 What's left to do?

• Documentation (including release notes)
• More comprehensive tests
• What else?

[cgay]

• Canonicalize CRLF to just LF

[cgay]

Fix backslash processing in make-hash-literal.

[cgay]

I think all of the above is done:

36f5ba6cf dfmc-reader: Add support for #"""quoted-symbol""" syntax e307b8613 dfmc-reader: Add support for raw string literals (#r" and #r""") 839320693 dfmc-reader: Add support for multi-line strings (""") 82f6ad7db (cgay/make-hash-literal) dfmc-reader: fix bug in make-hash-literal

Still to do: Make multi-line string literals respect The Rectangle Rule

[cgay]

Done in DEP 12 implementation.