* qemud/qemud.c: Re-factor out qemudExec() so that it can
        be used to launch dnsmasq.

        * qemud/conf.c: don't return argc from qemudBuildCommandLine()
        as exec() doesn't need it.

        * qemud/conf.c: Re-factor bits of conf.c so that:

          - qemudMakeConfigPath() can be re-used given another configDir
          - split qemudEnsureConfigDir() out of qemudSaveConfig() so
            that it may be re-used to create another configDir
          - split qemudScanConfigDir() out so that qemudScanConfigs()
            can scan multiple configDirs

        * qemud/conf.c: handle an unspecified MAC address,
        fix the argv freeing code in qemudBuildCommandLine()
        and fix copy and paste error in qemudGenerateXML()

        * qemud/conf.c, qemud/dispatch.c, qemud/driver.c,
          qemud/qemud.c: include autoconf's config.h

        * conf.[ch]: rename from config.[ch] so we can use
        autoconf's config.h

        * Makefile.am: update

        * driver.c, qemud.c: upd.