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.
OTHER: Fix typo that caused build error
OTHER: remove superfluous prototype
OTHER: Bump output priority of pulse
OTHER: Move XPOINTER_TO_* and X*_TO_POINTER macros to rb_collection.h, where they're still used.

These macros were supplanted by xmmsv. Added a FIXME since, as suggested, maybe a fix in waf is a better choice.