colorg-server: Split User back into Client and User.
This is so many clients may log in with the same name.
colorg.el: Have colorg-data to replace colorg-current-resource.
This is the first step towards multi-buffer support reentrency.
(colorg-associate-resource): Added, with local md5sum computation.
colorg.el: Cleanup server process silently when exiting Emacs.
colorg.el: Poll more often, for more comfort.