Merge pull request #3 from neonbunny/master

Bug fixes and initial Google Safe Browsing integration from @neonbunny - awesome and thanks again!
command line the address and hostname to bind to
style now in an external style sheet
more error handling
logo added to front html page
Minor code and readme changes including comments
Merge remote-tracking branch 'divemonkey/master'
Merge pull request #4 from divemonkey/master

Safe Browsing Updates
Re-added sanity check before calling safebrowsing, with additional comment to explain rationale.
Added range check for TCP port numbers and made use of argparse's "default" feature.