Updated jacSparsity() (removed old), #554
Revert "Updated jacSparsity() (removed old), #554"

This reverts commit 074be6460076cfc4aeddc5b99de594743ce14e39.
Updated jacSparsity() (removed old, second try), #554
Updated jacSparsity (cleanup), #554
Updated jacSparsity (enabled new), #554
Updated XFunction::jac (removed old), #554
Updated XFunction::jac (added new), #554
Updated jacobian(SXMatrix,SXMatrix), jacobian(MX,MX), (removed old), #554
Updated jacobian(SXMatrix,SXMatrix), jacobian(MX,MX), (added new), #554
Refactored Refactored LinearSolverInternal::spSolve