Version 2.1
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Version 2.1 is mainly a correction of version 2.0.


Velocity selector:
 - an error is corrected that occurred, if a very large number of 
   channels (> 500) was used.

Sample_powder:
 - The structure factor file could not be read because of a wrong path.
   This is corrected.

Source:
 - A similar error as in Sample_powder existed for user time/wavelength
   distribution files. Files could not be read after the use of 'Edit'.
   This works now.

 - It is now possible to give parameters that would give a zero neutron current in reality:
   - no divergence
   - one single wavelength
   - moderator of size zero
   - no time interval for pulses
   in these cases the 'current per trajectory' (or probability) is normalized: 
   p = flux/flux_amplitude/number_of_trajectories 
   To get realistic values for the neutron current it can be given now 
   (Parameter -c MeanModCurr_n/s)
   (Not included in the GUI)

 - the total neutron current is now seen as the flux integrated
   over a spherical angle of 2*pi (not 4*pi)


Spacewindow:
 - The Spacewindow module can now be used as a Beamstop:
   If the new parameter S is set to 1 (-S1), the window works in the opposite way.
   That means that the trajectory is lost, if it hits the window.
   Default is of course S=0, normal window.


Sample_sans:
 - the possibility to use scattering objects of different shapes is added.
   In addition to spheres, ellipsoids, cylinders and parallelepipeds can be used now.
   Therefore a capital letter for the shape must be added in the sample file:
   5th line '500.0' -> 'S 500.0' 
   - S: spheres        followed by the radius (in Angstroem)
   - E: ellipsoid      followed by 3 radii
   - P: parallelepiped followed by 3 numbers for length, width, height
   - C: cylinder       followed by 3 numbers radius 1, radius 2, height
   - I: isotropic scattering (no numbers necessary)

 - After the 'Sample_sans'-module absolute flux values are calculated now

 - The given Q-values that can be given are ignored: the given angular range
  (and the wavelength range) determines the Q-range now.


First steps are done to enable controlled interrupts to the simulation.
Pressing the Stop button means a controlled interrupt without loss of data,
pressing the Kill button means hard termination of processes.
This improvement is included in all modules mentioned above and 
'Guide', 'Chopper_disc' and 'Sample_reflectom'.
We expect it to work under both Unix and Windows, if only these modules are used
in the simulation. We are still testing it. But you can also try, if yoou like.

Changes to the VITESS GUI

- Adding your own module(s) to the VITESS GUI is very easy now. See usermodule.txt.
- You may tear off the output window to a separate window with a bigger font setting
  (BIG button) and re-fix it to the main VITESS window (SMALL button).
- Specify the width of scroll bars in the options menu.
- The Options/Apply settings menu re-builds the GUI with choosen settings. This
  is especially useful if you loaded some old gui file with strange settings, and
  want to change them. Windows caveat: if the window is too small after that,
  just resize it to the size you like.
- With the windows selfextracting file now comes Tcl/TK version 8.3.3.
