NodeAPI:
* modify getDefaultNode() to take a parameter list
  this list should be search for a sublist matching the name of the node; if found, sublist goes to the new node. otherwise, whole list goes to the new node.
* add node method to query data type support: bool Node::has_support<T>()

LinAlg:
* add CUSP sparse mat-vec implementations for CUDA nodes
* add CUBLAS GEMM for CUDA nodes
