Refactor crate into smaller private modules

BREAKING CHANGE: This removes the public `devicecode` and `revocation`
modules, instead re-exporting all of their public types from the root
of the crate. Most if not all of these types were already being
re-exported from the root; this change removes any import ambiguity.

examples/github_async.rs

@@ -14,7 +14,6 @@
 //!
 
 use oauth2::basic::BasicClient;
-// Alternatively, this can be `oauth2::curl::http_client` or a custom client.
 use oauth2::reqwest::async_http_client;
 use oauth2::{
     AuthUrl, AuthorizationCode, ClientId, ClientSecret, CsrfToken, RedirectUrl, Scope,

examples/google.rs

@@ -13,7 +13,7 @@
 //! ...and follow the instructions.
 //!
 
-use oauth2::{basic::BasicClient, revocation::StandardRevocableToken, TokenResponse};
+use oauth2::{basic::BasicClient, StandardRevocableToken, TokenResponse};
 // Alternatively, this can be oauth2::curl::http_client or a custom.
 use oauth2::reqwest::http_client;
 use oauth2::{

examples/google_devicecode.rs

@@ -15,9 +15,11 @@
 
 use oauth2::basic::BasicClient;
 // Alternatively, this can be oauth2::curl::http_client or a custom.
-use oauth2::devicecode::{DeviceAuthorizationResponse, ExtraDeviceAuthorizationFields};
 use oauth2::reqwest::http_client;
-use oauth2::{AuthType, AuthUrl, ClientId, ClientSecret, DeviceAuthorizationUrl, Scope, TokenUrl};
+use oauth2::{
+    AuthType, AuthUrl, ClientId, ClientSecret, DeviceAuthorizationResponse, DeviceAuthorizationUrl,
+    ExtraDeviceAuthorizationFields, Scope, TokenUrl,
+};
 use serde::{Deserialize, Serialize};
 
 use std::collections::HashMap;

examples/microsoft_devicecode_common_user.rs

@@ -1,7 +1,8 @@
 use oauth2::basic::BasicClient;
-use oauth2::devicecode::StandardDeviceAuthorizationResponse;
 use oauth2::reqwest::async_http_client;
-use oauth2::{AuthUrl, ClientId, DeviceAuthorizationUrl, Scope, TokenUrl};
+use oauth2::{
+    AuthUrl, ClientId, DeviceAuthorizationUrl, Scope, StandardDeviceAuthorizationResponse, TokenUrl,
+};
 
 use std::error::Error;
 

examples/microsoft_devicecode_tenant_user.rs

@@ -1,6 +1,6 @@
 use oauth2::basic::BasicClient;
-use oauth2::devicecode::StandardDeviceAuthorizationResponse;
 use oauth2::reqwest::async_http_client;
+use oauth2::StandardDeviceAuthorizationResponse;
 use oauth2::{AuthUrl, ClientId, DeviceAuthorizationUrl, Scope, TokenUrl};
 
 use std::error::Error;

examples/wunderlist.rs

@@ -14,16 +14,13 @@
 //! ...and follow the instructions.
 //!
 
-use oauth2::TokenType;
-use oauth2::{
-    basic::{
-        BasicErrorResponse, BasicRevocationErrorResponse, BasicTokenIntrospectionResponse,
-        BasicTokenType,
-    },
-    revocation::StandardRevocableToken,
+use oauth2::basic::{
+    BasicErrorResponse, BasicRevocationErrorResponse, BasicTokenIntrospectionResponse,
+    BasicTokenType,
 };
-// Alternatively, this can be `oauth2::curl::http_client` or a custom client.
 use oauth2::helpers;
+use oauth2::{StandardRevocableToken, TokenType};
+// Alternatively, this can be `oauth2::curl::http_client` or a custom client.
 use oauth2::reqwest::http_client;
 use oauth2::{
     AccessToken, AuthUrl, AuthorizationCode, Client, ClientId, ClientSecret, CsrfToken,