Merge pull request #35 from aashish24/netcdfreader_fix

Was referencing a deleted object that caused problems.
Set immediate mode rendering to on for STP generated scripts.

By default VTK uses display lists. For HPC runs where we do
a lot of renderings display lists can cause memory fragmentation
which can cause memory issues. So for STP generated scripts
we use immediate mode rendering.
Merge pull request #36 from aashish24/stp_use_immediate_mode_rendering

Stp use immediate mode rendering