OTHER: make some globals static
OTHER: fix nycli's server property

Mostly implementing source preference. As an extra allow more options.

Direct cause was a patch from Kristin ann <mistresskris@i2pmail.org> on the
mailing list. Reading the code around it, it was found that the behavior was
not as documented.
OTHER: Fix typo in error message
OTHER: rename --almost-all/-A to --all-tied/-t
OTHER: Add xmmsv_encode_url()

Encoding an url is not directly linked to medialib so
xmmsc_medialib_encode_url() is poorly named. This patch rename the
encode_url functions and put them with xmmsv_decode_url(),
deprecating the old names.
OTHER: Use new xmmsv_encode_url()
BUG(2574): Check for libmodplug/modplug.h
BUG(2573): Samba 4.0 uses pkg-config. Find libsmbclient.h properly.
OTHER: Add --stdin option to some cli commands

Allows to read a collection pattern from stdin when in inline mode
OTHER: Split xmms_avcodec_read, remove some duplicate code
OTHER: Output info on avcodec
BUG(2572): Use avcodec_decode_audio4
OTHER: Some compatibility with different avcodec versions
OTHER: Require avcodec_decode_audio4

This was introduced in versions 53.40.0 (ffmpeg) and 53.25.0 (libav) of
avcodec. Hence we drop compatibility for earlier versions.
OTHER: Output more info
OTHER: Break out xform object to separate file.
OTHER: Rename XMMS_*_PLUGIN XMMS_*_PLUGIN_DEFINE.
OTHER: Add ability to pass arguments to python generator.
OTHER: Add the possiblity to pass --with-builtin-plugins to waf configure

This will build selected plugins as objects and include them in the xmms2d binary.
OTHER: Allow overwriting lists of plugins

Previously the lists could only be extended, so it was impossible to remove
replaygain from the list of builtin plugins.