xml boilerplate
format individual nodes
display child->parent relationships
create xml for stdout redirection if necessary
chop off the stream redirection portion of a command

The nested string manipulation is ugly, but no worse than a bunch of
temporary variables.
Be nice and provide a detailed error message when multiple redirects are found.

Before the dax export would happily create commands referring to files like "&" and ">".
Merge branch 'rampantmonkey-dax_export_again'

Adds option to Makeflow which exports the workflow in XML following the DAX
Schema from Pegasus. (see -e option in Makeflow).