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

Replaces decoder_plugin_from_suffix().

Merge the two loops into one, and eliminate the GSList.

Export the decoder_plugins array.  The function
decoder_plugin_print_all_decoders() it is UI specific and should not
live in this backend library.

Remove the static integer hack, that's not thread safe and sucks.

This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.

Print the list of suffixes supported by each decoder, instead of
prining a list of all suffixes of all decoders with duplicates.

Currently, there is no way to dynamically load decoder plugins, thus
we don't need a dynamic list to manage them.

The decoder_plugin structs must never change.  Don't work with
non-const pointers.

"LOG_H" is a macro which is also used by ffmpeg/log.h.  This is
ffmpeg's fault, because short macros should be reserved for
applications, but since it's always a good idea to choose prefixed
macro names, even for applications, we are going to do that in MPD.

When there are standardized headers, use these instead of the bloated
os_compat.h.

InputPlugin to decoder_plugin, and no camelCase.

Since inputPlugin.c manages the list of registered decoders, we should
rename the source file.

The decoder_plugin instances are only used inputPlugin.c, so move them
from the header file.

"decoder plugin" is a better name than "input plugin", since the
plugin does not actually do the input - InputStream does.  Also don't
use typedef, so we can forward-declare it if required.

InputPlugin is the API which is implemented by a decoder plugin.  This
belongs to the public API/ABI, so move it to decoder_api.h.  It will
later be renamed to something like "decoder_plugin".

The decoder struct should later be made opaque to the decoder plugin,
because maintaining a stable struct ABI is quite difficult.  The ABI
should only consist of a small number of stable functions.

All of our main singleton data structures are implicitly shared,
so there's no reason to keep passing them around and around in
the stack and making our internal API harder to deal with.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7354 09075e82-0dd4-0310-85a5-a0d7c8717e4f