Fix two problems in the SSL implementation:
- A read operation should check the read buffer first to see if there's any
data present and use that first, before issuing a new read from the
socket.
- The read buffer was a member of the openssl_operation class, and a new
openssl_operation object is created for each read or write initiated by
the application. This meant that any surplus data from a previous read is
lost. Changed the buffer to be a member of the stream object.
[SVN r34738]
Christopher Kohlhoff