Renamed from with-buffer-prepared-for-font-lock and use
inhibit-modification-hooks rather than setting *-change-functions.
Update all functions to use the new name.
(jit-lock-first-unfontify-pos): New semantics (and doc).
(jit-lock-mode): Make non-interactive.
Don't automatically turn on font-lock.
Set jit-lock-first-unfontify-pos to indicate deferred-contextual mode.
Always use jit-lock-after-change.
Remove and restore font-lock-after-change-function.
(turn-on-jit-lock, jit-lock-after-fontify-buffer)
(jit-lock-after-unfontify-buffer): Remove.
(jit-lock-stealth-fontify):
Reset jit-lock-first-unfontify-pos to point-max rather than to nil.
(jit-lock-after-change): Set the `fontified' text-prop to nil.
Use consistent make-local-variable style for font-lock-fontified.
(jit-lock-fontify-buffer):
Don't bother checking for font-lock-mode and jit-lock-mode.
(jit-lock-fontify-buffer): New function for JIT refontification.
(jit-lock-mode): Fix docstring.
Use jit-lock-fontify-buffer for font-lock-fontify-buffer-function.
Remove jit-lock-after-change from the _local_ hook.
(jit-lock-function-1): Fix docstring.
restore-buffer-modified-p.
(with-buffer-prepared-for-font-lock): Use with-buffer-unmodified.
(jit-lock-function, jit-lock-stealth-fontify): Don't use
with-buffer-unmodified.
