Modified dates in source and header files.
The source and header files that were modified today have been updated
with the date.
Defined static functions for several standard vectors
Added static functions to matrix33.h for standard matrices
Updated date in vector3d.h
Function SlipPlane::calculateDislocationStresses now browsing all
defects for their stress fields.
Added check in Dislocation::stressFieldLocal to avoid division by zero.
If the distance between the source of the stress field and the point of
calculation is zero, the stress field is infinite because of a division
by zero. In this event a zero stress is returned.
Removed pointer check from SlipPlane::calculateDislocationStresses
The function used to check if the pointers of the two entities are the
same in order to avoid division by zero. Now the division by zero
safeguard is in place within the stressField function, therefore this
extra step here is redundant and has been removed.