Restructure modules

Modules are now separated into a fashion where the library can be used
for most use cases, without needing to compile the rest.

The core of serenity, with no features enabled, contains only the
struct (model) definitions, constants, and prelude. Models do not have
most functions compiled in, as that is separated into the `model`
feature.

The `client` module has been split into 3 modules: `client`, `gateway`,
and `http`.

`http` contains functions to interact with the REST API. `gateway`
contains the Shard to interact with the gateway, requiring `http` for
retrieving the gateway URL. `client` requires both of the other features
and acts as an abstracted interface over both the gateway and REST APIs,
handling the event loop.

The `builder` module has been separated from `utils`, and can now be
optionally compiled in. It and the `http` feature are required by the
`model` feature due to a large number of methods requiring access to
them.

`utils` now contains a number of utilities, such as the Colour struct, the
`MessageBuilder`, and mention parsing functions.

Each of the original `ext` modules are still featured, with `cache` not
requiring any feature to be enabled, `framework` requiring the `client`,
`model`, and `utils`, and `voice` requiring `gateway`.

In total the features and their requirements are:

- `builder`: none
- `cache`: none
- `client`: `gateway`, `http`
- `framework`: `client`, `model`, `utils`
- `gateway`: `http`
- `http`: none
- `model`: `builder`, `http`
- `utils`: none
- `voice`: `gateway`

The default features are `builder`, `cache`, `client`, `framework`,
`gateway`, `model`, `http`, and `utils`.

To help with forwards compatibility, modules have been re-exported from
their original locations.

1 files changed, 10 insertions, 8 deletions

diff --git a/src/client/context.rs b/src/client/context.rs
index 27e5ab9..22216b1 100644
--- a/src/client/context.rs
+++ b/src/client/context.rs
@@ -1,18 +1,19 @@
 use std::sync::{Arc, Mutex};
-use super::gateway::Shard;
-use super::rest;
 use typemap::ShareMap;
-use ::utils::builder::EditProfile;
+use ::gateway::Shard;
+use ::http;
 use ::internal::prelude::*;
 use ::model::*;
 
 #[cfg(feature="cache")]
 use super::CACHE;
+#[cfg(feature="builder")]
+use ::builder::EditProfile;
 
 /// The context is a general utility struct provided on event dispatches, which
 /// helps with dealing with the current "context" of the event dispatch.
 /// The context also acts as a general high-level interface over the associated
-/// [`Shard`] which received the event, or the low-level [`rest`] module.
+/// [`Shard`] which received the event, or the low-level [`http`] module.
 ///
 /// The context contains "shortcuts", like for interacting with the shard.
 /// Methods like [`set_game`] will unlock the shard and perform an update for
@@ -21,8 +22,8 @@ use super::CACHE;
 /// A context will only live for the event it was dispatched for. After the
 /// event handler finished, it is destroyed and will not be re-used.
 ///
-/// [`Shard`]: gateway/struct.Shard.html
-/// [`rest`]: rest/index.html
+/// [`Shard`]: ../gateway/struct.Shard.html
+/// [`http`]: ../http/index.html
 /// [`set_game`]: #method.set_game
 #[derive(Clone)]
 pub struct Context {
@@ -76,6 +77,7 @@ impl Context {
     /// ```rust,ignore
     /// context.edit_profile(|p| p.username("Hakase"));
     /// ```
+    #[cfg(feature="builder")]
     pub fn edit_profile<F: FnOnce(EditProfile) -> EditProfile>(&self, f: F) -> Result<CurrentUser> {
         let mut map = Map::new();
 
@@ -88,7 +90,7 @@ impl Context {
                 map.insert("email".to_owned(), Value::String(email.clone()));
             }
         } else {
-            let user = rest::get_current_user()?;
+            let user = http::get_current_user()?;
 
             map.insert("username".to_owned(), Value::String(user.name.clone()));
 
@@ -99,7 +101,7 @@ impl Context {
 
         let edited = f(EditProfile(map)).0;
 
-        rest::edit_profile(&edited)
+        http::edit_profile(&edited)
     }
 
     /// Sets the current user as being [`Online`]. This maintains the current