chunkbuffer: removed unused method and arg

revlog: reduce memory usage in addgroup - use a buffer to extract the delta from a chunk - avoid concatenating to a compressed delta - use a buffer to directly extra full text from a trivial delta - delete chunk and delta objects after use

mpatch: allow buffer objects for input

Merge with crew Those crew folks are getting lazy about pulling from upstream before committing.

test-convert-darcs: don't let $HOME/.darcs pollute the test environment

convert: refactor sink initialisation, to remove hardcoding of hg We also introduce options to explicitly set the source and destination repository types. Improve testing of corner cases a little.

convert: add default constructor for converter_sink

convert: make contents of "extra" dict available from sources, for sinks. This breaks hash preservation for hg->hg conversion, as each converted change gets a convert_revision item added to its extra dict. Ugh.

convert: rename convert_svn to svn_source

convert: report errors more meaningfully if run with --traceback