[Merge][Feature] -r1754 from trunk: Add a mode to SuperLU where apply uses freshly allocated vectors.

Previously the two vectors are allocated in
the first call to apply. These got resused in subsequent calls to apply
and are deallocated in the destructor. Using the new mode these vectors are allo
cated
at the beginning and deallocated at the end of each apply method. This allows
using the same instance of superlu from different threads.



[[Imported from SVN: r1881]]