daemon: Install dring to libexec and edit templates at install time.
Executables are typically installed under bin/, sbin/ or libexec, rather than lib/. The problem was noticed when trying to use Jami with a Guix relocatable pack, which only wraps executables found under the above locations. Since dring is a daemon and should not be run directly by users under normal circumstances, the convention is to use the libexec directory, according to the File Hierchy Standard 3.0. Also tackled in this change is the substitution of the Autoconf variables at installation time rather than configuration time, as per the GNU Coding Standards. The following solution is taken from https://github.com/gentoo/eudev/pull/183/commits, which in turn is adapted from the Autoconf manual (c.f.: info "(autoconf)Installation Directory Variables"). * bin/Makefile.am (ringlibdir): Delete variable. * bin/dbus/Makefile.am (do_subst): New variable. (cx.ring.Ring.service): Derive from the cx.ring.Ring.service.in template. [HAVE_WIN32]: (ringlib_PROGRAMS): Rename to ... (bin_PROGRAMS): ... this. [HAVE_OSX, RING_DBUS]: Likewise. * bin/dbus/cx.ring.Ring.service.in (Exec): Adust. * globals.mk (ringlibdir): Delete variable. * configure.ac [with_dbus] <AC_CONFIG_FILES>: Remove bin/dbus/cx.ring.Ring.service. Also remove the LIBDIR variable, no longer used. Fix indentation. Thanks to Vladimir Stoiakin for providing feedback on this change. Change-Id: I845bf2bd590a9457e70ca173027217b8f164d713