split replay view into BaseContentView and ReplayView
refactor RewriteLiveHandler into RewriteLiveView
add additional tests for framed and non-framed mode
default to framed replay!
memento support enabled by default, togglable via 'enable_memento' config property
supporting timegate and memento apis, no timemap yet
supporting pattern 2.3 for archival and pattern 1.3 for proxy modes
also:
simplify exception hierarchy a bit more, move down to utils
make WbRequest and WbResponse extensible with mixins (eg for memento)