clean up pick-an-index for inclusion in a paper
fix type comment

(thanks, Sam!)
adjust plot so that it uses "rvm" for the verification model
scribble/base: add `#:{column,row,cell}-properties` arguments to `tabular`

The new arguments greatly simplify adding properties such as alignment
and (HTML) background colors to table cells. For example, to make a
table with 'right alignment for the left-hand column, 'center alignment
for the second column, and 'left alignment for all remaining columns:

 (tabular cells
          #:sep (hspace 1)
          #:column-properties '(right center left))

Also, make `color-property` and `background-color-property` recognized
as table-cell style properties.

Finally, implement horizontal alignment for text rendering.
Fix tc-let for mutable variables.

Closes PR 14415.
Add test case for PR 11747.

Closes PR 11747. This was fixed at some point.
Avoid a parameter for controlling resolve caching

The parameter dereference slowed down type-checking
new-metrics.rkt to about 28s from 16s on DrDr.

Instead of the parameter, explicitly remove items from the
cache during type alias setup.
Add test case for PR12985.

Closes PR 12985.
adjust #:enum arg to redex-check to be back like 6.0,
add #:uniform-at-random argument and #:in-order argument
change redex-check's default strategy to do both
enumeration and random generation in a manner
supported by our study
note redex-check change in redex history
Remove unused clause arguments in tc-let-unit.
Make let correctly implement the TC-Let rule from the paper.
Add smart constructors for Result and tc-result.
Use filters when typechecking using tc-body.

Closes PR 11920.