csh.login: set PATH again (if empty) to prevent interpreter error (#1744106)
    aliases: add pcp user (#1744091)
    lang.csh: fix several variable substitution bugs and typos (#1746749)
    don't set LANG as a per-shell variable
    fix lang.csh script so it doesn't break tcsh -e scripts II (#1620004)
    use full path for non-builtins in csh.cshrc, csh.login, lang.csh, lang.sh and profile (#1747493)