Show expanded tree by default

[camachojua]

First of all I want to thank you for your effort to improve the user experience on Redmine. I was wondering if I could make a change to set the expanded view of trees as a default. Currently I tried to modify (without success) the file assets/custom.jquery.treetable.js to generate this behavior specifically setting initialState = 'expanded' and calling the expand() function under Node.prototype._initialize.

I'm aware of the performance penalty discussed in #30 and #8, but the number of tickets for my projects will not exceed the hundreds. Where can I start to look to make this little change?