Clarify in header, how planes of reflection should be written.

Author: Lomholy

mcstas-comps/contrib/Monochromator_bent_complex.comp

@@ -19,7 +19,7 @@
 * This component only differs in the fact that it allows and forces the user 
 * to set every single parameter for every single crystal in the crystal array.
 * An exception to this rule is the plane of reflection, for which one can 
-* choose a single plane of reflection, and that will work for all crystals
+* choose a single plane of reflection, and that will work for all crystals.
 *
 *
 * %Parameters
@@ -29,7 +29,7 @@
 * xthickness: [m] Thickness of each crystal without bending.
 * radius_x:   [m] Radius of the circle the monochromator bends on in the plane. Can be negative.
 * radius_y:   [m] Radius of the (very large) circle the monochromator bends on as a side effect of the horizontal bending. The code assumes that it is so small that it does not affect the points of intersection appreciatively of the crystal.
-* plane_of_reflection:     [string] The plane of reflection from the material. The list of possible reflections can be seen in the source code. 
+* plane_of_reflection:     [string] The plane of reflection from the material. The list of possible reflections can be seen in the source code. Each plane must be separated by a ";", like "Si400;Si111".
 * angle_to_cut_horizontal: [degrees] Angle between cut and normal of crystal slab, horizontally
 * mosaicity:                [arcmin] Gaussian mosaicity of the crystal. Always the horizontal mosaicity
 * mosaic_anisotropy: [1] Anisotropy of the mosaicity, changes vertical mosaicity to be mosaic_anisotropy*mosaicity