Move the contract profiler to its own collection.

Should become its own package once we split up the collects.

Requested by Eli, to reduce the dependencies of the profiler collection.
Add match*? to unstable/match
Fix union merging

Trying to merge (and thus resolve) applications of struct
types would cause infinite looping on type instantiation
if the struct type used both a union and recursion.

Closes PR 13821
Improve TR test case
Fix type of gensym.
Fix dist-specs.
Remove leftover define/match docs
Superficial pattern for wildcard that doesn't bind.
add some missing pref items docs
add a column-width guide; defaults to 102 characters, but disabled
added history not about column width guide
fix `hash-copy' on weak hash tables

Closes PR 13838
setup/cm: fix some dependency tracking on deleted files

Based on a report and patch from Tobias Hammer.
Add an equality checking argument to `member`
Update TR base environment
Remove `memq`, `memv`, `member` from #%kernel

These are now implmented purely in Racket on all
platforms.
Fix build. Forgot to add this file in c305dba.

Apologies to any future git bisect-ers
Fix cstartup and the build.

Somehow this got messed up in c305dba though I'm
not sure how.
redex: add `where-make-prefix-pict' and `where-combine' for typesetting
raco setup: fix for bootstrap