This change was done to avoid confusion with TCP/IP raw sockets. Native sockets
module represents handling native system low level socket API in general and is
not just limited anyhow to TCP/IP raw sockets.
A stub lib/deprecated/pure/rawsockets.nim module has been added as
compatibility layer for old code using rawsockets, so this change will not
break existing code.
The tasyncexceptions test has been added which tests for this incorrect
exception handling behaviour. The problem was that the exception was
raised inside a callback which was called from a previously finished async
procedure. This caused a "Future already finished" error. The fix was to
simply reraise the exception if the retFutureSym is already finished.
sleepAsync was added to help with the reproduction of this test. It should
also be useful for users however.
Finally some debug information was added to futures to help with future
bugs.
Implicit registration of an fd now only occurs when a new socket is
created (in socket() or accept()). This makes the implementation much
simpler, changes to the linux version will follow.
Reworked detection of a file descriptor being closed with epoll (in the
case of sockets it is when the remote host disconnects). Ensured that
events are only updated when they change.
