Cookies are now collected during redirects, one the last cookie
of a given name is kept. Cookies are then set by looking for
the right cookie name (instead of what viewer 3 does: just
use the last cookie that was set).
This fixes the merchant outbox.
This fixes the problem that existed with received headers:
The server sends some headers ("set-cookie") more than once
in the same reply, which cannot be stored in std::map.
The old code just ignored the additional cookies, while
curlthreading3 (since the introduction of AIHTTPHeaders)
caused an assertion.
AIHTTPReceivedHeaders is written around a std::multimap
and allows to retrieve multiple headers with the same key.
Also, it is case insensitive so that if a server sends
"Content-Type" it will still find it (the viewer looks for
"content-type").
This creates a separate events interface structure
for CurlResponderBuffer (AICurlResponderBufferEvents)
for dealing with received HTTP headers.
The headers are passed to the Responder, but only
if the class derived from Responder implements
completedHeaders (otherwise it makes little sense
to even decode the headers).
Basically this is a reimplementation of the functionality
of the old LLHTTPClientURLAdaptor class.
