Minor mode to selectively hide/show code and comment blocks.
With a prefix argument ARG, enable the mode if ARG is positive,
and disable it otherwise. If called from Lisp, enable the mode
if ARG is omitted or nil.
When hideshow minor mode is on, the menu bar is augmented with hideshow
commands and the hideshow commands are enabled.
The value '(hs . t) is added to `buffer-invisibility-spec'.
The main commands are: `hs-hide-all', `hs-show-all', `hs-hide-block',
`hs-show-block', `hs-hide-level' and `hs-toggle-hiding'. There is also
`hs-hide-initial-comment-block' and `hs-mouse-toggle-hiding'.
Turning hideshow minor mode off reverts the menu bar and the
variables to default values and disables the hideshow commands.
Lastly, the normal hook `hs-minor-mode-hook' is run using `run-hooks'.
Uses keymap `hs-minor-mode-map', which is not currently defined. (fn &optional ARG)