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/finit.c

@@ -75,7 +75,6 @@ char *fstab     = NULL;
 char *sdown     = NULL;
 char *network   = NULL;
 char *hostname  = NULL;
-char *runparts  = NULL;
 char *osheading = NULL;
 
 uev_ctx_t *ctx  = NULL;		/* Main loop context */