Consider removing unused internal legacy code

[lread]

Problem/Opportunity
While hunting for what macros rewrite-clj exposes, I noticed a couple of unexposed/unused/undocumented/untested ones under the internal rewrite-clj.node.whitespace namespace:

• with-newline-fn
• with-count-fn

They have an associated a couple of associated dynamic vars:

• *newline-fn*
• *count-fn*

Proposed Solution
Delete them.

Alternative Solutions

• Expose them and support them.
• Leave them in and mark them as deprecated.

Additional context
I'll try to determine if these are relevant today, and if anybody is using them.
If not, out they go.

Action
I'll follow up.