various fixes for scripts:

- [crend] increase azi/ele tolerance for IR matching in Crend table generation
- [fastconv] prevent crash due to hardcoded truncation point for BRIRs shorter than
  273 timeslots (needs a proper fix)
- [tdrend] suppress error printout from script
- [general] support FIR-E convention by squeezing out emitter dimension
- [general] allow cartesian as well as spherical type data from SOFA