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, 15 insertions, 12 deletions

diff --git a/src/model/channel/private_channel.rs b/src/model/channel/private_channel.rs
index 910daa2..9e2aec1 100644
--- a/src/model/channel/private_channel.rs
+++ b/src/model/channel/private_channel.rs
@@ -2,7 +2,9 @@ use std::fmt::{Display, Formatter, Result as FmtResult};
 use std::io::Read;
 use super::deserialize_single_recipient;
 use ::model::*;
-use ::utils::builder::{CreateMessage, GetMessages};
+
+#[cfg(feature="model")]
+use ::builder::{CreateMessage, GetMessages};
 
 /// A Direct Message text channel with another user.
 #[derive(Clone, Debug, Deserialize)]
@@ -29,6 +31,7 @@ pub struct PrivateChannel {
     pub recipient: Arc<RwLock<User>>,
 }
 
+#[cfg(feature="model")]
 impl PrivateChannel {
     /// Broadcasts that the current user is typing to the recipient.
     pub fn broadcast_typing(&self) -> Result<()> {
@@ -114,14 +117,14 @@ impl PrivateChannel {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the [`the limit`], containing the number of unicode code points
     /// over the limit.
     ///
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
-    /// [`CreateMessage`]: ../utils/builder/struct.CreateMessage.html
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
+    /// [`CreateMessage`]: ../builder/struct.CreateMessage.html
     /// [`Message`]: struct.Message.html
-    /// [`the limit`]: ../utils/builder/struct.CreateMessage.html#method.content
+    /// [`the limit`]: ../builder/struct.CreateMessage.html#method.content
     #[inline]
     pub fn edit_message<F, M>(&self, message_id: M, f: F) -> Result<Message>
         where F: FnOnce(CreateMessage) -> CreateMessage, M: Into<MessageId> {
@@ -206,12 +209,12 @@ impl PrivateChannel {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the above limit, containing the number of unicode code points
     /// over the limit.
     ///
     /// [`ChannelId`]: ../model/struct.ChannelId.html
-    /// [`ClientError::MessageTooLong`]: enum.ClientError.html#variant.MessageTooLong
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
     #[inline]
     pub fn say(&self, content: &str) -> Result<Message> {
         self.id.say(content)
@@ -229,11 +232,11 @@ impl PrivateChannel {
     /// # Errors
     ///
     /// If the content of the message is over the above limit, then a
-    /// [`ClientError::MessageTooLong`] will be returned, containing the number
+    /// [`ModelError::MessageTooLong`] will be returned, containing the number
     /// of unicode code points over the limit.
     ///
     /// [`ChannelId::send_file`]: struct.ChannelId.html#method.send_file
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
     /// [Attach Files]: permissions/constant.ATTACH_FILES.html
     /// [Send Messages]: permissions/constant.SEND_MESSAGES.html
     pub fn send_file<F, R>(&self, file: R, filename: &str, f: F) -> Result<Message>
@@ -248,12 +251,12 @@ impl PrivateChannel {
     ///
     /// # Errors
     ///
-    /// Returns a [`ClientError::MessageTooLong`] if the content of the message
+    /// Returns a [`ModelError::MessageTooLong`] if the content of the message
     /// is over the above limit, containing the number of unicode code points
     /// over the limit.
     ///
-    /// [`ClientError::MessageTooLong`]: ../client/enum.ClientError.html#variant.MessageTooLong
-    /// [`CreateMessage`]: ../utils/builder/struct.CreateMessage.html
+    /// [`ModelError::MessageTooLong`]: enum.ModelError.html#variant.MessageTooLong
+    /// [`CreateMessage`]: ../builder/struct.CreateMessage.html
     /// [`Message`]: struct.Message.html
     #[inline]
     pub fn send_message<F: FnOnce(CreateMessage) -> CreateMessage>(&self, f: F) -> Result<Message> {