table: removed types on internal codes

changed the token type of the null, assignment, print, and input
internal codes to default token type - a type is not needed for these
codes because they are not produced by the parser

modified the test output stream insert operator function for tokens
where the debug name is now output by default for a token (necessary for
the codes modified above) and since the internal function types only
output the debug name, the case for these were removed (goes to default
case)