Bug 4055

/etc/zshenv:
	keeps adding elements to the path.  Annoying when
	zsh is called from within zsh (such as a zsh shell
	in an emacs buffer started from an zsh shell in an
	xterm itself started from a zsh shell run from
	.xsession
	But at least it puts them at the end, so it's not
	too intrusive
/etc/zshrc:
	most of the crap has nothing to do in there and
	should be in /etc/skel/.zshrc instead.  Else it's
	a real pain the ass for the user to override them.
	setting `umask' in the zshrc file is a bad idea.
	especially since it is sourced after ~/.zshenv and
	~/.zprofile which means that it
	overrides and user setting of `umask' in those
	files.  It should be in /etc/zshenv
	or /etc/zprofile if anywhere.
	setting USER is evil.  USER is already set
	automatically, leave it as it is.  Same thing
	for LOGNAME.
	is set `path' and then `PATH' although these are
	one and the same variable, so you end up adding
	$HOME/bin twice (and this gets repeated ad-nauseaum
	in the same way as the /etc/zshenv settings if
	you execute zsh from within zsh).
	`bindkey -e' is also annoying and unnecessary:
	unless VISUAL or EDITOR contains `vi' the bindings
	default to `-e' already.  Adding the explicit
	`bindkey' defeats this useful feature.