Doxygen comments.

Formfactors: integrand of imaginary part is real.

Transform reduced to 3x3 rotation.

Tried removal of Rotate from Geometry which however is required by IsGISAXS07.
Will be reverted in a minuted.

- Correct little typos

Conflicts:
	Core/Core.pro
	Examples/Performance/perf_history.txt
	Fit/Fit.pro

  (typedef Geometry::BasicVector3D<int> IndexVector3D
   now in ISelectionRule.h).
Class description for SimpleSelectionRule.

Forbid shorthand a*b, request a.dot(b) or dotProduct(a,b).
Remove "virtual" from ~BasicVector3D.
Provide templated implementation for almost all methods,
  resolving issue #237.

Conflicts:
	Fit/Fit.pro