Revert "Add custom NFA logging to nfa_regexp.log"

This reverts commit b17b22e4b198bccdfdcae3aea693f5ca08d8a1ac.
Only enable regexp debugging with DEBUG_REGEXP
Make 'lispwords' a global-local option

Multiple filetypes cannot currently use different values of 'lispwords',
even though it makes sense to have multiple values of this setting for
different lisps.

The scheme, clojure, and art filetypes currently set local values of
'lispwords', then reset them with 'setlocal lispwords<' in an undo hook.

This patch makes this actually work.
Add test for 'lispwords' global-local scope
Change 'lispwords' in Clojure filetype for new global-local scope

- 'lispwords' is moved to the ftplugin file from the indent file to
  mirror the Scheme filetype

- The value is now assigned on one line, instead of attempting to blank
  the setting with `setlocal lispwords=`, which is now tantamount to
  `setlocal lispwords<`
Merge branch 'lispwords-global-local' into guns

* lispwords-global-local:
  Change 'lispwords' in Clojure filetype for new global-local scope
  Add test for 'lispwords' global-local scope
  Make 'lispwords' a global-local option