Require 'cl during byte-compilation/interactive load, for the `assert' macro.

Require 'cl during byte-compilation/interactive load, for the `assert' macro.
(allout-mode-deactivate-hook): New hook, is run when allout mode deactivates.
(allout-developer): New allout customization subgroup.
(allout-run-unit-tests-on-load): New allout-developer
customization variable, when true allout unit tests are run towards end of file
load/eval.
(allout-inhibit-auto-fill): Disable auto-fill activity even during
auto-fill-mode.
(allout-resumptions): Removed, to be replaced by...
(allout-add-resumptions): Register variable settings to be reinstated by
`allout-do-resumptions'.  The settings are made buffer-local, but the
locality/globality of the suspended setting is restored on resumption.
(allout-do-resumptions): Reinstate all settings suspended using
`allout-add-resumptions'.
(allout-test-resumptions): Unit tests (and intermediate variables) for
resumptions.
(allout-tests-globally-unbound, allout-tests-globally-true)
(allout-tests-locally-true): Intermediate variables for resumptions unit tests.
(allout-overlay-preparations): Replaces `allout-set-overlay-category'.
(allout-exposure-category): Replaces 'allout-overlay-category variable.
(allout-mode): Use `allout-add-resumptions' and `allout-do-resumptions'
instead of retired `allout-resumptions'.  For hook functions, use `local'
parameter so hook settings are created and removed as
buffer-local settings.  Revise (resumptions) setting auto-fill-function so it
is set only if already active.  (The related fill-function settings are all
made in either case, so that activating auto-fill-mode activity will have the
custom allout-mode behaviors (hanging indent on topics, if configured for it).
Also, remove all allout-exposure-category overlays on mode deactivation.
(allout-hotspot-key-handler): New function extracted from
`allout-pre-command-business', so the functionality can be used for other
purposes, eg as a binding in an overlay.
(allout-pre-command-business): Use new `allout-hotspot-key-handler'.
(allout-auto-fill): Respect new `allout-inhibit-auto-fill' customization
variable.
(allout-run-unit-tests): Run the (currently quite small) repertoire of unit
tests.  Called just before the provide iff user has customized
`allout-run-unit-tests-on-load' non-nil.