Remove bb_ prefixes from xfuncs.c (and a few other places), consolidate

things like xasprintf() into xfuncs.c, remove xprint_file_by_name() (it only
had one user), clean up lots of #includes...  General cleanup pass.  What I've
been doing for the last couple days.

And it conflicts!  I've removed httpd.c from this checkin due to somebody else
touching that file.  It builds for me.  I have to catch a bus.  (Now you know
why I'm looking forward to Mercurial.)

coreutils/ls.c

@@ -37,15 +37,7 @@ enum {
 /************************************************************************/
 
 #include "busybox.h"
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <getopt.h> /* struct option */
-#include <sys/ioctl.h>
-#include <sys/sysmacros.h>     /* major() and minor() */
-#include <time.h>
+#include <getopt.h>
 
 /* what is the overall style of the listing */
 #define STYLE_COLUMNS   (1U<<21)	/* fill columns */
@@ -535,7 +527,7 @@ static struct dnode **list_dir(const char *path)
 
 	dn = NULL;
 	nfiles = 0;
-	dir = bb_opendir(path);
+	dir = warn_opendir(path);
 	if (dir == NULL) {
 		status = EXIT_FAILURE;
 		return (NULL);	/* could not open the dir */