The result shall be positive.

This is the version in Debian Stretch (stable).

MPD has minSdkVersion=21 which is above all the checks here.

Since nfs_stat_async is deprecated.

This is the version in Debian Jessie (oldstable), a reasonable "old
enough" version to keep support for.

add 2 preferences to:
 - enable Wakelock when MPD is running (prevent suspend)
 - run MPD on boot

and display MPD logs

 - <uses-permission> must be before <application>
 - specify allowBackup (default)

- add Settings: Activity to start / stop MPD Service (Main).

- Main is a service that run in foreground with a notification. See
  Service.startForeground documentation for more details.

- Main.Client is used to control the service: start or stop it and also receive
  callbacks when service encounters an error, is killed, is started or is
  stopped.

- Main.start to start the service without any fallback.

A Java object to send logs on the android side.

javah is deprecated.

Eliminate yet another access to the global ConfigData instance.

Eliminate a use of GetGlobalConfig().

When using a database that was not created with a WebDAV music_directory
(i.e., if using a remote database, on which updates happen locally) and
using the Curl storage plugin, MPD would previously send GET requests that
had unescaped spaces in them.  This change uses Curl's URL-encode API to
solve this.