Big tool rename.

As promised, this is the "big tool rename" patch.  The primary differences
since 0.99.6 are:

  (1) git-*-script are no more.  The commands installed do not
      have any such suffix so users do not have to remember if
      something is implemented as a shell script or not.

  (2) Many command names with 'cache' in them are renamed with
      'index' if that is what they mean.

There are backward compatibility symblic links so that you and
Porcelains can keep using the old names, but the backward
compatibility support  is expected to be removed in the near
future.

Signed-off-by: Junio C Hamano <junkio@cox.net>

merge-index.c

@@ -0,0 +1,135 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "cache.h"
+
+static const char *pgm = NULL;
+static const char *arguments[8];
+static int one_shot, quiet;
+static int err;
+
+static void run_program(void)
+{
+	int pid = fork(), status;
+
+	if (pid < 0)
+		die("unable to fork");
+	if (!pid) {
+		execlp(pgm, arguments[0],
+			    arguments[1],
+			    arguments[2],
+			    arguments[3],
+			    arguments[4],
+			    arguments[5],
+			    arguments[6],
+			    arguments[7],
+			    NULL);
+		die("unable to execute '%s'", pgm);
+	}
+	if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status)) {
+		if (one_shot) {
+			err++;
+		} else {
+			if (!quiet)
+				die("merge program failed");
+			exit(1);
+		}
+	}
+}
+
+static int merge_entry(int pos, const char *path)
+{
+	int found;
+	
+	if (pos >= active_nr)
+		die("git-merge-index: %s not in the cache", path);
+	arguments[0] = pgm;
+	arguments[1] = "";
+	arguments[2] = "";
+	arguments[3] = "";
+	arguments[4] = path;
+	arguments[5] = "";
+	arguments[6] = "";
+	arguments[7] = "";
+	found = 0;
+	do {
+		static char hexbuf[4][60];
+		static char ownbuf[4][60];
+		struct cache_entry *ce = active_cache[pos];
+		int stage = ce_stage(ce);
+
+		if (strcmp(ce->name, path))
+			break;
+		found++;
+		strcpy(hexbuf[stage], sha1_to_hex(ce->sha1));
+		sprintf(ownbuf[stage], "%o", ntohl(ce->ce_mode) & (~S_IFMT));
+		arguments[stage] = hexbuf[stage];
+		arguments[stage + 4] = ownbuf[stage];
+	} while (++pos < active_nr);
+	if (!found)
+		die("git-merge-index: %s not in the cache", path);
+	run_program();
+	return found;
+}
+
+static void merge_file(const char *path)
+{
+	int pos = cache_name_pos(path, strlen(path));
+
+	/*
+	 * If it already exists in the cache as stage0, it's
+	 * already merged and there is nothing to do.
+	 */
+	if (pos < 0)
+		merge_entry(-pos-1, path);
+}
+
+static void merge_all(void)
+{
+	int i;
+	for (i = 0; i < active_nr; i++) {
+		struct cache_entry *ce = active_cache[i];
+		if (!ce_stage(ce))
+			continue;
+		i += merge_entry(i, ce->name)-1;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int i, force_file = 0;
+
+	if (argc < 3)
+		usage("git-merge-index [-o] [-q] <merge-program> (-a | <filename>*)");
+
+	read_cache();
+
+	i = 1;
+	if (!strcmp(argv[i], "-o")) {
+		one_shot = 1;
+		i++;
+	}
+	if (!strcmp(argv[i], "-q")) {
+		quiet = 1;
+		i++;
+	}
+	pgm = argv[i++];
+	for (; i < argc; i++) {
+		char *arg = argv[i];
+		if (!force_file && *arg == '-') {
+			if (!strcmp(arg, "--")) {
+				force_file = 1;
+				continue;
+			}
+			if (!strcmp(arg, "-a")) {
+				merge_all();
+				continue;
+			}
+			die("git-merge-index: unknown option %s", arg);
+		}
+		merge_file(arg);
+	}
+	if (err && !quiet)
+		die("merge program failed");
+	return err;
+}