28609a2c77
With the removal of the old session command implementation, the code that used it can be removed or replaced with newer constructs. As a result, the backend protocol no longer does any session command processing. The three buffer types, GWBUF_TYPE_SESCMD_RESPONSE, GWBUF_TYPE_RESPONSE_END and GWBUF_TYPE_SESCMD as well as their related macros are no longer used and can be removed.