Avoid GLib.

Replaces Reset() and eliminates the AudioFormat parameters from the
Convert() method.

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

Replaces GLib's GError.

Look up top-level config options by enum (= integer), not by name
string.

Some compilers are very picky, but we really aren't interested in the
return value.

Some compilers are very picky, but we really aren't interested in the
return value.

Declaring the global variable _CRT_fmode is a documented hack.  What
an ugly platform!

Log to stderr instead of the default stdout.  We need a pristine
stdout for the conversion result.

Ensure that the pcm_convert() length argument is aligned to the sample
size.

Assign default value only if none was given on the command line.

After we've been hit by Large File Support problems several times in
the past week (which only occur on 32 bit platforms, which I don't
have), this is yet another attempt to fix the issue.

An asterisk means that this attribute should not be enforced, and
stays whatever it used to be.  This way, some configuration values
work like masks.