Demangle C++ names in text output

[arichardson]

It would be nice if the text output would demangle C++ function names.

This might not be useful for machine-readable but with libxo it is be possible to have different output for each case:

d   display     Only emit field for display styles (text/HTML)
e   encoding    Only emit for encoding styles (XML/JSON)

Alternatively we could add a -soaap-demangle-names flag that would do it whatever the output format is.

[trombonehero]

+1: the Chromium analysis requires lots of gratuitous cat soaap.json | c++filt > tmp.json && mv tmp.json soaap.json. It would be nice for SOAAP to handle this internally.