Some Changes

I've did working on a new Spline some changes as were noticed as missing. They are more or less like a bugfixing/features completeness and they are in short:
- Boo expressions will work for integer based expressions
- almost all cases (excluding cases that can work with impracticable large shape count) will update tree-view correctly. As code level some cases will get easier to make populating this code easier to do (it can be defined a root node, and all nodes will be added in cascade)