processor.py: Closes snapshot temp file and use root path.

Closes chfoo/wpull#128
processor.py: Removes buggy and unneeded robots.txt special case.

Removes --no-strong-robots option.
urlfilter.DemuxURLFilter: Adds result a mapping of names to verdicts.

Closes chfoo/wpull#126
app.py: Hooks in phantomjs_snapshot option.