Update gitignore
Rename make_pipe.hh to socketpair.hh
Move make_pipe to static member function of UnixDomainSocket
Rename make_pipe() -> make_pair()
Make PacketShell store a (non-stripped) UnixDomainSocket
file_descriptor.hh: g++ < 4.9 requires a virtual destructor to inherit
Make Socket/SecureSocket/TunDevice inherit from FileDescriptor
Make UnixDomainSocket have private constructor
socketpair.cc: Implement send_fd/recv_fd
packetshell.cc: Write directly to sibling's TUN device (big CPU win)
socketpair.cc: Simplify passing of file descriptor
Share the SSL context and free SSL objects when connection ends
FileDescriptor and children: counts reads and writes
poller.cc: require callbacks to service fd in ready direction
secure_socket.cc: properly check error on SSL_accept
Refactor backing stores into their own class
http_proxy.cc: Finish refactor (save with arbitrary BackingStore)
backing_store.cc: synchronize access to HTTPDiskStore::save() to be safe