Add support for SysV-only scripts in runparts

This patch extens the SysV compatibility support in Finit by adding
support for limiting `runparts` to run only SNNfoo, or KNNfoo, style
scripts from a directory.

Additionally, by default `runparts` now runs entirely in the background
without any progress.  To enable progress, an optional argument has been
added to the runparts command line.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/plugin.c

@@ -230,7 +230,7 @@ void plugin_script_run(hook_point_t no)
 	} else
 		env[2] = NULL;
 
-	run_parts(path, NULL, env, 0);
+	run_parts(path, NULL, env, 0, 0);
 }
 #else
 void plugin_script_run(hook_point_t no)