Grouped environment variable calculations

I moved some calculations that were often performed multiple times to siminfomanager to avoid overhead.

The result is that Case600 of the BesTest results was evaluated in 51s instead of 71s on my pc. I implemented a spliceFunction for the evaluation of hCon to avoid a discontinuity. Due to this change the unit test results changed a bit. Otherwise the unit tests seem to be consistent.

@rubenbaetens can you verify these changes?