This function was previously documented to return only nil or t. This
has been changed to nil/'autosaved'/non-nil. The new 'autosaved'
value means that the buffer is modified, but that it hasn't been
-modified after the last auto-save.
+modified since the time of last auto-save.
---
** 'with-silent-modifications' also restores buffer autosave status.
+++
*** 'restore-buffer-modified-p' can now alter buffer auto-save state.
With a FLAG value of 'autosaved', it will mark the buffer as having
-been auto-saved after the last modification.
+been auto-saved since the time of last modification.
---
*** New minor mode 'isearch-fold-quotes-mode'.