SFS Toolbox 2.1.0

New version including several improvements for time-domain NFC-HOA simulations, new virtual line sources for WFS and NFC-HOA, the ability to set t=0 for time-domain simulations to the start of the virtual source, and as usual lots of small bug fixes.

NEWS:

- make conf struct mandatory
- add new start message
- fix handling of 0 in least squares fractional delays
- fix NFC-HOA order for even loudspeaker numbers to N/2-1
- add conf.wfs.hpreFIRorder as new config option (was hard coded to 128
  before)
- speed up secondary source selection for WFS
- rename chromajs colormap to yellowred
- fix tapering_window() for non-continuous secondary sources
- remove cubehelix colormap as it is part of Octave
- add conf.wfs.t0 option with is useful, if you have more than one
  virtual source
- virtual line sources are now available for monochromatic WFS and NFC-HOA
- allow arbritrary orders for time-domain NFC-HOA simulations