Test-updated main.c lines 1396 to 1400

Starting to update --explain text.

src/flac/main.c

@@ -1393,10 +1393,11 @@ void show_explain(void)
 	usage_header();
 	usage_summary();
 	printf("For encoding:\n");
-	printf("  The input file(s) may be a PCM WAVE, Wave64, RF64 file, AIFF (or uncompressed\n");
-	printf("  AIFF-C) file, or raw samples. The output file(s)  will be in native FLAC\n");
-	printf("  or Ogg FLAC format\n");
+	printf("  The input file(s) may be PCM in WAVE, Wave64, RF64 or AIFF/AIFC file, or \n");
+	printf("  raw samples.  The output file(s) will be in native FLAC or Ogg FLAC format.\n");
 	printf("For decoding, the reverse is true.\n");
+	printf("In addition, both input and output can be a FLAC / Ogg FLAC file.  The file\n");
+	printf("will then be decoded and encoded anew, and tags will be transferred.\n");
 	printf("\n");
 	printf("A single INPUTFILE may be - for stdin.  No INPUTFILE implies stdin.  Use of\n");
 	printf("stdin implies -c (write to stdout).  Normally you should use:\n");