Refactor the conversion functions to classes and pass an instance to
the new function AllocateConvert().

-fixes SIGABRT when mpd is started from a previously paused state
-regression introduced by commit: f5a923b9:
'OutputAll: convert to class, move instance to class Partition'

-input_audio_format was previously declared using the static modifier
ensuring it was zero-initialised by default
-the current default-initialised input_audio_format contains garbage at
runtime which allows the AudioFormat.IsDefined() 'fail fast' test in
MultipleOutputs::Update to pass and the SIGABRT follows in
AudioOutput::Open when passed the invalid input_audio_format struct
-switching AudioFormat.IsDefined() for AudioFormat.IsValid() is an
alternative workaround

Fixes crash bug because mpd_connection_get_async() was called without
a connection.

-fixes regression introduced by:
 '8d6fedf8 [PATCH] Mixer: add class MixerListener'
-listener.OnMixerVolumeChanged() called GetVolume() which attempted to acquire
the lock but as per 'pa_threaded_mainloop_lock()' documentation:
This function may not be called inside the event loop thread. Events that are
dispatched from the event loop thread are executed with this lock held
-this patch seperates the underlying action of GetVolume() into a new
GetVolumeInternal() function, to be called only when the lock is already held, as
is the case for the listener.OnMixerVolumeChanged() call

Has been superseded by the previous commit.

Don't wait for an optimistic write to fail.  This is an improved
workaround for the infamous Raspberry Pi bug (see commit af991765).
It works much better and comes without the negative side effects.  The
old workaround is now obsolete.

Add enum InputResult which is a tri-state.  Input plugins may now fail
and just become unavailable.

Move code from CreateConfiguredDatabase() and add XDG support.  This
implements an automatic Linux fallback for the setting "db_file" if
none was specified.

Add class Context which wraps the Android/Java Context class and add a
JNI wrapper for method Context.getCacheDir().

Stole my own code from another project :-)

Hard-coded path.  Will be replaced soon.

This was accidently disabled when storage plugins were introduced.

The SDK for level 9 cannot be downloaded anymore.

Quick hack to allow using the database without GLib (for Android).

We're not using external storage yet, but as soon as we will, we only
need to read music files, not write them.

Omit a few methods that are not applicable.

This was bugged, because it did not scale the "size".