Password reset (#448)

* Password reset

* Various improvements and fixes for password reset

- Reorganize src/mail.rs to make it  cleaner
- add a build_mail function
- only make the requests invalid after 2 hours
- avoid infintely-growing list of requests by deleting them once completed, or after 24 hours
- avoid sending many requests for the same user
- validate the password reset form

* Avoid locking so many times

Fix durations

* Remove old requests even if the current one is not valid

* Remove unused feature

* Also remove the custom_derive and plugin features while we are at it

* Forgot a 0 è_é

* Avoid panicking while owning a request lock

* Use master branch of lettre so that we can build with the latest OpenSSL

* Fix the debug mailer

templates/session/password_reset.rs.html

@@ -0,0 +1,16 @@
+@use template_utils::*;
+@use templates::base;
+@use routes::session::NewPasswordForm;
+@use validator::ValidationErrors;
+
+@(ctx: BaseContext, form: &NewPasswordForm, errors: ValidationErrors)
+
+@:base(ctx, i18n!(ctx.1, "Reset your password"), {}, {}, {
+  <h1>@i18n!(ctx.1, "Reset your password")</h1>
+
+  <form method="POST">
+    @input!(ctx.1, password (password), "New password", form, errors.clone(), "minlenght=\"8\"")
+    @input!(ctx.1, password_confirmation (password), "Confirmation", form, errors.clone(), "minlenght=\"8\"")
+    <input type="submit" value="@i18n!(ctx.1, "Update password")" />
+  </form>
+})