Trying another parser.
Finished making blk[] definitions inherit Block.
changed core while loop to use Blocks.
cleaned up various syntax.
Accomodate reversed symbols for Invoke and Yield
Added symbols to block objects.
Removed Block.children. Children array defined on each instance.
Lots of debugging.
Fix import alias.
Better removal of beginning and ending markers.
Added options and plugins back in.
Replace cpparser with Object parser.