Further memory optimization and bug fix: utilize views of matrix columns for  response gradients in Approximation::add().
Further memory optimization and bug fix: utilize views of matrix columns for 
response gradients in Approximation::add().


git-svn-id: c6750f7dd89925e309f580f56430152d063ff36c@492 aa0779c3-6ec2-4b84-a212-a405c134cd8d

pemryan/DAKOTA,pemryan/DAKOTA,pemryan/DAKOTA,pemryan/DAKOTA,pemryan/DAKOTA,pemryan/DAKOTA,pemryan/DAKOTA