Refactor with the help of Clippy (#462)

We add clippy as our build — also rectifying the missing `plume-cli` build!

In the next step we follow clippy's advise and fix some of the "simple" mistakes in our code, such as style or map usage.

Finally, we refactor some hard bits that need extraction of new types, or refactoring of function call-types, especially those that thread thru macros, and, of course functions with ~15 parameters should probably be rethought.

src/routes/mod.rs

@@ -1,3 +1,4 @@
+#![warn(clippy::too_many_arguments)]
 use atom_syndication::{ContentBuilder, Entry, EntryBuilder, LinkBuilder, Person, PersonBuilder};
 use rocket::{
     http::{
@@ -8,9 +9,45 @@ use rocket::{
     request::{self, FromFormValue, FromRequest, Request},
     response::NamedFile,
 };
+use rocket_i18n::I18n;
 use std::path::{Path, PathBuf};
 
-use plume_models::{Connection, posts::Post};
+use plume_models::{
+    Connection,
+    users::User,
+    posts::Post,
+    db_conn::DbConn,
+};
+
+use Worker;
+use Searcher;
+
+pub struct PlumeRocket<'a> {
+    conn: DbConn,
+    intl: I18n,
+    user: Option<User>,
+    searcher: Searcher<'a>,
+    worker: Worker<'a>,
+}
+
+impl<'a, 'r> FromRequest<'a, 'r> for PlumeRocket<'a> {
+    type Error = ();
+
+    fn from_request(request: &'a Request<'r>) -> request::Outcome<PlumeRocket<'a>, ()> {
+        let conn = request.guard::<DbConn>()?;
+        let intl = request.guard::<I18n>()?;
+        let user = request.guard::<User>().succeeded();
+        let worker = request.guard::<Worker>()?;
+        let searcher = request.guard::<Searcher>()?;
+        rocket::Outcome::Success(PlumeRocket {
+            conn,
+            intl,
+            user,
+            worker,
+            searcher,
+        })
+    }
+}
 
 const ITEMS_PER_PAGE: i32 = 12;
 
@@ -45,7 +82,7 @@ impl Page {
         }
     }
 
-    pub fn limits(&self) -> (i32, i32) {
+    pub fn limits(self) -> (i32, i32) {
         ((self.0 - 1) * ITEMS_PER_PAGE, self.0 * ITEMS_PER_PAGE)
     }
 }