Use font-lock-flush and font-lock-ensure if available
Use font-lock-flush and font-lock-ensure if available

`font-lock-fontity-buffer' is only intended for interactive use.  Emacs
v25.1 adds `font-lock-flush' and `font-lock-ensure' as replacements.  A
lot of reading revealed that we actually have to call both functions.

tarsius/emacsql,skeeto/emacsql,emacsmirror/emacsql