remove artanis/auth.scm
update TODO
TPL module update.
* artanis/artanis.scm:
  Add: tpl->html, convert sxml or tpl-file to HTML.
  Add: tpl->response, convert sxml or tpl-file to HTML and emit it
       as the response.
  Fix: redirect-to, add content-type when redirect URL.
* artanis/tpl.scm:
  Add: tpl-render-from-file, read tpl file then render.

* artanis/utils.scm:
  Add: local-eval-string, like local-eval, but for string.
add *session-path*
session update.
* artanis/session.scm:
  Add: save-session-to-file, persist session to file.
  Add: delete-session-file, delete session file.
  Update: misc update.
cookie update
update example, add embedded tpl example