parser cleanup, steps toward removing all mess to do with premature use of node type. main parse loop now takes a node vector ptr rather than a specific node, so it can be invoked and a node created by the caller *afterwards*.
ok
finally got rid of the dumb expr/exprblock parser hack. nodes are created after 'parse_block_nodes' gives the necassery delimiter information ( { , , ,}=anon-struct-init vs { ; ; ; }=compound-expressino , and later maybe [,,,] vs [ ; ; ;]  etc...