Use nqp::getcfh to implement getc.

Also bump NQP_REVISION to a version that supports this op on both JVM
and Parrot.
Just use a once block for is DEPRECATED and be done with it
Make sure a problem in reporting, does not inhibit the report
jnthn++ tells me the {} were not needed
Mark "exists" as DEPRECATED, change all calls of .exists to .exists_key|pos
Mention the :exists adverb, instead of 'exists_key'
Start getting defterm handling in place.

This enables things like:

    constant term:<inator> = "I'll be back";
Allow #`[space] in regexes (Unrelated to RT#77522)
Merge pull request #210 from Mouq/nom

Allow #`[space] in regexes (Unrelated to RT#77522)
Move empty set symbol to right place, but alas still doesn't work
Add empty set as a term.  Not sure how to go on from here, though  :-(
Add Action for empty set
use nqp's unlink, rather than parrot's
bump nqp revision
Mark all .delete methods as DEPRECATED, add delete_key|pos methods as needed
Change all calls to '.delete' to .delete_key|pos
s/rule/token/ for LTM's sake.
attach_docs can happily be a method.
heredoc rarely need create a Cursor.

Saves 20,000 or so Cursor allocations in CORE.setting.
Make sure [3,*-3]:delete works