The "loop_count" configuration parameter allows the user to set how
many times a module with backward loops shall loop. "0" (the default)
means a module is not allowed to use backward loops at all. "-1"
enables inifinite looping.

This patch allows the user to configure the mikmod decoder plugin to loop
modules. It adds a configuration parameter to the mikmod decoder called
"loop" which can be "no" (the old behaviour, default) or "yes" to allow
modules to use backward loops.

The new class Path only holds a string pointer without being
responsible for allocation/deallocation.  The FileSystem.hxx library
accepts Path arguments instead of AllocatedPath, to avoid forcing
callers to allocate another string object.

Decouple some more from GLib.

Replacing GLib macros.

Prepare to migrate away from GLib.  Currently, we're still using GLib
as a backend.

Reduce heap allocator overhead.

Since Debian package 1:0.8.8.4-4, the pkg-config file does not contain
-I/usr/include/libmodplug anymore, and we need to add the
"libmodplug/" prefix to the #include line.

Migrate the remaining callers to FatalError().

Use only ConfigData.hxx in plugin sources to reduce header
dependencies.

Reduce header dependencies.

Replaces GLib's GError.

FfmpegDecoderPlugin: Allocate the interleaved buffer as needed instead of using an arbitrary big constant.

Also, save a memcpy when FFmpeg outputs interleaved audio.

Fixes build with FFmpeg 2.0.

Player_LoadTitle() returns an aligned pointer in libmikmod-3.2 that
cannot be freed with free(). The correct way to do this now is
MikMod_free() which extracts the original pointer from the buffer and
frees that.
Signed-off-by: Christoph Mende <mende.christoph@gmail.com>

Now that even Debian stable has picked up version 0.8, we can safely
make this a requirement, and remove a lot of old cruft.

This old version has been obsolete for many years - time to remove it.

Allow reusing Tag instances.

Avoid duplicating the tag.