An SVN::Dump object represents a Subversion dump.

This module follow the semantics used in the reference document (the file
notes/fs_dumprestore.txt in the Subversion source tree):

* A dump is a collection of records (SVN::Dump::Record objects).
* A record is composed of a set of headers (a SVN::Dump::Headers object), a set
of properties (a SVN::Dump::Property object) and an optional bloc of text (a
SVN::Dump::Text object).
* Some special records (delete records with a Node-kind header) recursively
contain included records.