Replaces awesome_nested_set gem with a simple and more robust implementation of nested sets....
Replaces awesome_nested_set gem with a simple and more robust implementation of nested sets.
The concurrency tests added in this commit trigger dead locks and/or nested set inconsistency with awesome_nested_set.
git-svn-id:
http://svn.redmine.org/redmine/trunk@13841 e93f8b46-1217-0410-a6f0-8f06a7374b81
