Speed up URLUtils for url canonicalization

Speed up URLUtils for url canonicalization by removing the dependency of InetAddress. Please be aware that URLUtils is still a little be off from Google's spec that it produces result different form google's reference design. Google's reference can be seen from expression_test.py from https://code.google.com/p/google-safe-browsing/downloads/detail?name=googlesafebrowsing-opensource-code-v0.3.zip&can=2&q=