GME starts all track indexes at zero, but subtune prefixes
start at one. This fixes an off-by-one error during track
enumeration.

GME starts all track indexes at zero, but subtune prefixes
start at one. This fixes an off-by-one error during track
enumeration.

If you load an NSFE file (which has embedded track titles),
then attempt to load an M3U file, it causes GME to lose all
information found in the NSFE file. This adds a check that
the M3U file exists before attempting to load.

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

Speed up container_scan() again, by eliminating the need to call
scan_file() for each item.

Broken by commit 0abee77e

Got lost in 0abee77e

Replaces decoder_data() and others.

Replaces decoder_initialized().

Prepare for a Decoder API redesign based on an abstract class with
virtual methods.

Fixes http://bugs.musicpd.org/view.php?id=4432

Use simple string and path parsing functions instead of GLib's
g_pattern_match(), which was used in a very clumsy way.

There is duplicate code in the two.