Add new table, node_type_attributes, which will eventually encompass
most of what is in the node_types table (and node_types_auxtypes). The goal is to make most of the type information free form key/value pairs so that type information is more extensible. This commit simply creates the table and populates it with initial info using init_nodeattrs.pl. I expect this script to change, but it can be rerun later so no big deal.