Re: 'M-o' ('facemap-keymap') has now been removed until March 10th 2021

[Paul W. Rankin]

Unless I'm fundamentally missing something, the new command font-lock-update 
only duplicates the functionality of existing command font-lock-fontify-buffer, 
and adds some confusion...

When font-lock-mode is active and font-lock-update is called with ARG, the 
command unfontifies the buffer and deactivates font-lock-mode. Wut? Makes no 
sense for a command called font-lock-update...

The docstring states that font-lock-update only fontifies the accessible 
portion of the buffer. This isn't true; the command calls 
font-lock-fontify-region, which widens the restriction unless 
font-lock-dont-widen is non-nil, which is nil by default.

Given the removal of M-o M-o to fontify block, the addition of C-x x f to 
update fontification is a good idea, but let's just have it call 
font-lock-fontify-buffer and get rid of this command.

If someone wants specifically to toggle font-lock-mode, they'd just call M-x 
font-lock-mode. If they're toggling font-lock-mode enough for it to become an 
issue, they'd bind that to a key.