Makefiles do not honour DESTDIR setting

[toodlelew]

The julius Makefiles (Makefile/Makefile.in) do not honour the traditional Unix DESTDIR setting used to re-root the install. This makes "staged" installation, where the installer may not have permission to install in the root tree, or may want to package the installation tree for the OS distribution's preferred installation package tool, difficult.

See https://www.gnu.org/prep/standards/html_node/DESTDIR.html for a description on the use of DESTDIR