Optimisations and bugfixes in Greycat

Greycat backend

You will need to reindex from 1.2.0-rc2 if you were using the Greycat backend. There have been some major changes:

• Greycat on RocksDB now works on Windows, by disabling compression.
• Greycat on RocksDB is now deprecated. Instead, you are recommended to use Greycat on top of LevelDB: it is shown to be faster in all our tests.
• Rewrote use of embedded Lucene indexing in the Greycat backends: the indices are now properly time-aware (but not world-aware yet).
• Upgraded Greycat to version 11.

Time-aware indexing

• Model.types produces time-aware type wrappers as well.
• Added the timeline EOL query engine. You can run the same query in a time-agnostic way against all known versions of the model, and receive a sequence of (timepoint, result) pairs.
• Added Model.allInstancesNow and Model.allInstancesAt.

Optimisations and bugfixes

• UI: large SVN-based imports may take a while to download - provide status reports on import progress.
• SVN: speed up imports by reusing the connection as much as possible.
• Fix for regression in 1.2.0-rc1 in proxy resolution of Modelio-style fragmented models.
• Speed up Model.allContents by turning it into a dedicated lazy collection, with optimized .size implementations whenever possible.