A forward compatibility package `cl-generic', which provides
`cl-defgeneric' and `cl-defmethod' for older Emacsen, is now
available from GNU Elpa.

`make bootstrap' now uses this script.  If that part of the bootstrap
process fails, then you can also run it manually.  See the commentary
at the beginning of the script for usage instructions.

Suppress warnings about `defgeneric' and `defmethod' being obsolete.
Compiling the drone `emacsql' results in many such warnings, which
distract from other potential warnings, which actually should be
addressed.  Because `emacsql' wants to stay compatible with Emacsen
before v25.1 it cannot switch to `cl-defgeneric' and `cl-defmethod'
and I don't want to see warnings about that for the next few years.

Also direct all of Emacs' stderr to stdout because `message' prints
to stderr instead of stdout).