Consolidate lisp/jsonrpc.el logging in single events buffer

Consolidate lisp/jsonrpc.el logging in single events buffer

For inferior processes having useful stderr, it is no longer
cumbersome to switch between different buffers to correlate error
messages with transport-level JSONRPC messages.

The existing stderr and stdout buffers can still be found hidden away
from the normal buffer list.

An original idea of Tobias Rittweiler <trittweiler@gmail.com>.

* lisp/jsonrpc.el (initialize-instance jsonrpc-process-connection):
Setup after-change functions stderr buffer.  Hide stderr and stdout
buffers.
(jsonrpc--log-event): Don't output extra newline.  Tweak log format.
(Version): Bump to 1.0.10