RTTI adds overhead to the binary, and we don't need that.

We don't use exceptions currently.  Since allowing exceptions means a
lot of overhead, this commit disables the feature.

Allows eliminating more dead code.  Adds two more C++ options that may
reduce the binary size.

Conflicts:
	src/PlaylistSave.cxx

The song's URI must be UTF-8, not filesystem character set.

Fixes minor Windows compatibility problem.

Implements Mantis feature request 3582.

Interleaving was completely wrong.  This code was never used, so it
didn't have an effect.

Works around assertion failure in decoder_timestamp().

Use av_get_sample_fmt_string() to obtain a human-readable string.

API simplification.

Implement the "scan_stream" method that can read tags from any
input_stream object.  This requires a FLAC__IOCallbacks implementation
based on the input_stream API.

g_file_error_quark() is meant to be used with the GFileError enum
which does not correspond with errno, but must be converted with
g_file_error_from_errno().

At the same time, this removes g_strerror() use for
g_file_error_quark().

Improved support for scanning http:// resources.

Merge common code.

Use the new FLACMetadataIterator C++ class, which is more powerful.

Not using libFLAC++ because this library adds a lot of overhead due to
virtual method calls.  This new class library is zero-overhead.

This has been deprecated by the "embcue" playlist plugin.

The "opusinfo" program complained about preskip value that was too
small.  This commit uses OPUS_GET_LOOKAHEAD to obtain the number of
frames that shall be silence at the beginning.

Improves quality by not squeezing 32 bit samples down to 16 bit, and
then back to 32 bit floating point.  Reduces CPU usage by skipping a
conversion step.