cookie: Handle cookies without "=".

Fix regression introduced in 38a4152. Closes chfoo/wpull#206
options: Use --html-parser html5lib as default

Closes chfoo/wpull#208
document.util: Add missing import
app: Whitelist exceptions that are not crashes for crash message
Downgrade SSLVerficationError to ProtocolError if --no-check-certificate

Closes chfoo/wpull#209
Rename SSLVerficationError to SSLVerificationError
setup.py: Drop lxml as hard requirement