Prevent Meson from running Android-x86 binaries.  That will fail
because the Android standard libraries are most likely not installed.

The Curl plugin requires libexpat in order to work these days, so we should
download and build it in order to get the plugin enabled on Windows.

First commit for issue #69

Closes #232

libmad has been unmaintained for a long time, and it fails to build on
Windows.  I could go and fix libmad's broken configure script, but I
prefer to just assign MP3 decoding to FFmpeg for now.

Closes #228

Enable the NFS storage plugin on Android.

Closes #226

For version numbers such as OpenSSH's, e.g.: "7.2p2"

MPD doesn't use this feature anyway.