loader: Compress dump file and rework truncated dump handling
When dumping a subversion repository to file before loading it, compress that file using gzip while producing it. It enables to save significant disk space while dumping a large repository.
Also rework the way how truncated dump is handled now dump file is compressed by providing the expected max revision number to be loaded by svnadmin. If the number of loaded revisions matches, we can safely continue the partial loading of the repository.
Prio this change, the size of dump file for svn://tug.org/texlive was more than 80Gb while its compressed version has a size of 46,9Gb.
Depends on !153 (closed)
Migrated from D8787 (view on Phabricator)