[fix #772] and fix broken `cider-eval-and-get-value`

1efc9fa broke `cider--all-ns` and almost all of `cider-browse-ns`.  Fix  #772 for real and return `read` to `cider-eval-and-get-value` with an optional `no-read` argument. Also clean a couple of historical one-line functions which were used only once.