Teach fsck and prune about the new location of temporary objects

Since 5723fe7e, temporary objects are now created in their final destination
directories, rather than in .git/objects/. Teach fsck to recognize and
ignore the temporary objects it encounters, and teach prune to remove them.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-fsck.c

@@ -377,6 +377,10 @@ static void fsck_dir(int i, char *path)
 			if (de->d_name[0] != '.')
 				break;
 			continue;
+		case 14:
+			if (prefixcmp(de->d_name, "tmp_obj_"))
+				break;
+			continue;
 		case 38:
 			sprintf(name, "%02x", i);
 			memcpy(name+2, de->d_name, len+1);