[PATCH] enable build support without systemd compatibility libraries

[Linda A. Walsh]

Simon McVittie wrote:
> Shouldn't the check be the other way round, so we check for libsystemd
> if available, and fall back to libsystemd-* if not?
>
> If you want to reduce binary size in a packaged distribution, it would
> seem reasonable to package the compat *.pc files in a -dev/-devel
> package, but not package the compat libraries: that's API-compatible
> (but not ABI-compatible) with systemd < 209, and would allow dbus to be
> compiled without changes.
>   
----
    If they are compat libraries, why not package them in a compat 
package so the content
is clear.  Dev[el] packages aren't usually a place to bury compat options...