Similar to commit 31ab78ae

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

Has been moved to class InputStream long ago.

Remove the "whence" parameter that is not actually necessary, and only
complicates the InputStream implementations.

Replace InputPlugin attributes.

Replaces the method Close().

Prepare for adding virtual methods.

Decouple some more from GLib.

Replaces GLib's GError.

Add the interface ArchiveVisitor.

Eliminate input_stream_init() and input_stream_deinit().