This Makefile fragment is meant to be included by packages that
require a libjpeg implementation.  jpeg.buildlink3.mk will:

      * set JPEGBASE to the base directory of the libjpeg files;
      * set JPEG_TYPE to the libjpeg implementation used.

There are three variables that can be used to tweak the selection of
the libjpeg implementation:

JPEG_DEFAULT is a user-settable variable whose value is the default
      libjpeg implementation to use.

JPEG_ACCEPTED is a package-settable list of libjpeg implementations
      that may be used by the package.

This .mk is broadly based on fam.buildlink3.mk,v 1.7, and
currently supports selection between the default "graphics/jpeg"
and the alternative "graphics/libjpeg-turbo".

(dsainty)