agenda: Rename %8sync (and %8sync-*) to 8sync (and 8sync-*)

agenda: Rename %8sync (and %8sync-*) to 8sync (and 8sync-*)

* 8sync/agenda.scm (%8sync, %8sync-delay, %8sync-run, %8sync-run-at)
  (%8sync-run-delay, %8sync-port, %8sync-port-remove, catch-%8sync):
  Rename, removing % sign.  Rename all references to other %8sync-foo
  in definitions and comments as well.
  (catch-8sync): Removed aliased version.
  (make-async-request, setup-async-request): Rename references of
  %8sync-foo to 8sync-foo.

* 8sync/systems/irc.scm (make-basic-irc-handler):
* 8sync/systems/web.scm (receive-http-conn):
* tests/test-agenda.scm: Rename all %8sync-foo to 8sync-foo.