Prep to release again.
Let's call that 0.1.0.
Another release :-)
Drop another version.
Support rebuild_ancestry in MySQL and PostgreSQL, as well as SQLite3.
I've added tentative support for MS-SQL, too.
Add test to ensure that ancestry_string is still derived properly whe…
…n scopes are in effect.
Implement Node.rebuild_ancestry, which re-computes all ancestry_strin…
…gs based on parent-child relationships.