Fixed neighbor_node_array to properly handle boundary nodes.
Fixed neighbor_node_array to properly handle boundary nodes.

Fixed
=====

* neighbor_node_array now properly handles boundary nodes. Use the keywords
  open_boundary_nodes, and closed_boundary_nodes to specify which nodes are
  on the boundary. Only the id of nodes on active links are recorded, otherwise
  their ids are set as BAD_INDEX_VALUE.



Carralex/landlab,landlab/landlab,decvalts/landlab,landlab/landlab,RondaStrauch/landlab,amandersillinois/landlab,csherwood-usgs/landlab,cmshobe/landlab,csherwood-usgs/landlab,laijingtao/landlab,Carralex/landlab,RondaStrauch/landlab,ManuSchmi88/landlab,SiccarPoint/landlab,Carralex/landlab,landlab/landlab,cmshobe/landlab,decvalts/landlab,SiccarPoint/landlab,ManuSchmi88/landlab,RondaStrauch/landlab,cmshobe/landlab,ManuSchmi88/landlab,amandersillinois/landlab,laijingtao/landlab