patch: add support for git delta hunks When creating patches modifying binary files using "git format-patch", git creates 'literal' and 'delta' hunks. Mercurial currently supports 'literal' hunks only, which makes it impossible to import patches with 'delta' hunks. This changeset adds support for 'delta' hunks. It is a reimplementation of patch-delta.c from git : http://git.kernel.org/cgit/git/git.git/tree/patch-delta.c