use complete events in crox

[andjo403]

to reduce the size of the generated json file
fixes #47

[wesleywiser]

Nice work! I'm seeing a reduction on the regex crate's profiling data from 35.6mb to 19.4mb which is very good.

[andjo403]

@wesleywiser you hade made it very easy to do with the iterator.
the crate that I looked at when I wanted this was script from servo where the file went from 1.4 GB to 0.7 GB and that was enough to get chrome to show the file after 5 min and using 6 GB memory :)