Redmine 2.0

I updated the redmine 2.0 branch to work with jQuery (which redmine is using now instead of Prototype library since 2.1.0(?)). This also incorporates the patch from redmine issue #2024 so I don't have to patch redmine. 

One glitch I haven't been able to figure out is the edit is able to update the task via ajax, but an actual page refresh is needed to update dependent tasks (or another "move", which puts them where they should have been after the previous move, i.e. it lags by one operation). The ajax response contains information for updating them, but the ruby code is pulling old data for some reason that I haven't been able to figure out. Perhaps the caching in issue_dependency_patch.rb has something to do with this?