Move ./vsdistrib to cb-gdb-vsextension repository, and update README.md

It should be emphasized that there are now two branches that are required to be present:

origin/master is supposed to be stable and buildable at all times

origin/relcan, for "release candidate", is used by the camelian-packages repositories package-
building routines for creating packages.  My procedure lately has been to fuss and fiddle
with relcan until the completed final packages work properly, and then merge relcan into
master.  That merge gets tagged as a release version, and at that point ../include/version.h
is incremented.

vsdistrib/Makefile

-
-.PHONY : all install
-
-
-all:
-# 	do nothing
-
-install:
-	./install_vsix

vsdistrib/install_vsix

-#! /bin/sh
-
-set -e
-
-#
-# This script used to work, and then it stopped, apparently because
-# Microsoft changed something in VSCode, or maybe because something
-# changed in X, probably as a security measure.  The error message
-# is
-# /usr/lib/xorg/Xorg.wrap: Only console users are allowed to run the X server
-# 
-# So, until I can sort that out, the extension will have to be installed
-# manually.
-
-VSIX=`ls --sort=time cbl-gdb*.vsix | head -n1`
-
-echo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-echo ""
-echo "Please run the following command manually:  (The X server won't"
-echo "run it from a script.)"
-echo ""
-echo code --install-extension vsdistrib/$VSIX
-echo ""
-echo !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-exit 0
-
-SUDO=sudo
-
-# For reasons I don't understand, this routine fails when run as part of 
-# a Debian package build. When it got tedious, I just decided to elmininate it.
-
-if "X"$DESTDIR = "X" ; then
-	# Find the most recent VSIX package, and install it
-	if test -x `command -v code` ; then
-		if test "X"$VSIX != "X" ; then 
-			echo "Installing $VSIX"
-			if test "X"$SUDO_USER != "X" ; then
-				# They must be running as 'sudo make install'
-				$SUDO -u $SUDO_USER code --force --install-extension $VSIX
-			else
-				# They must simply be running as 'make install', meaning that
-				# the user must've taken ownership of /usr/local/
-				code --force --install-extension $VSIX
-				fi
-			fi
-		fi
-	fi