Big repository reorganization

The code is divided in three crates:
- plume-common, for the ActivityPub module, and some common utils
- plume-models, for the models and database-related code
- plume, the app itself

This new organization will allow to test it more easily, but also to create other tools that only reuse a little part of
the code (for instance a Wordpress import tool, that would just use the plume-models crate)

plume-models/src/blog_authors.rs

@@ -0,0 +1,24 @@
+use diesel::{self, QueryDsl, RunQueryDsl, ExpressionMethods, PgConnection};
+
+use schema::blog_authors;
+
+#[derive(Queryable, Identifiable)]
+pub struct BlogAuthor {
+    pub id: i32,
+    pub blog_id: i32,
+    pub author_id: i32,
+    pub is_owner: bool,
+}
+
+#[derive(Insertable)]
+#[table_name = "blog_authors"]
+pub struct NewBlogAuthor {
+    pub blog_id: i32,
+    pub author_id: i32,
+    pub is_owner: bool,
+}
+
+impl BlogAuthor {
+    insert!(blog_authors, NewBlogAuthor);
+    get!(blog_authors);
+}