Import open-vcdiff-0.8.3, an RFC 3284 encoder/decoder for VCDIFF
Differencing and Compression, into the packages collection:

	An encoder and decoder for the format described in RFC 3284:  "The
	VCDIFF Generic Differencing and Compression Data Format." The encoding
	strategy is largely based on Bentley-McIlroy 99:  "Data Compression
	Using Long Common Strings." A library with a simple API is included,
	as well as a command-line executable that can apply the encoder and
	decoder to source, target, and delta files.  A slight variation from
	the draft standard is defined to allow chunk-by-chunk decoding when
	only a partial delta file window is available.