Merge branch 'db/delta-applier' into db/text-delta

* db/delta-applier: vcs-svn: let deltas use data from preimage vcs-svn: let deltas use data from postimage vcs-svn: verify that deltas consume all inline data vcs-svn: implement copyfrom_data delta instruction vcs-svn: read instructions from deltas vcs-svn: read inline data from deltas vcs-svn: read the preimage when applying deltas vcs-svn: parse svndiff0 window header vcs-svn: skeleton of an svn delta parser vcs-svn: make buffer_read_binary API more convenient vcs-svn: learn to maintain a sliding view of a file Makefile: list one vcs-svn/xdiff object or header per line Conflicts: Makefile vcs-svn/LICENSE