Added leave server and other stuff

lib/Client/InternalClient.js

@@ -69,6 +69,46 @@ var InternalClient = (function () {
 		});
 	};
 
+	//def leaveServer
+
+	InternalClient.prototype.leaveServer = function leaveServer(srv) {
+		var self = this;
+		return new Promise(function (resolve, reject) {
+			var server = self.resolver.resolveServer(srv);
+			if (server) {
+
+				request.del(Endpoints.SERVER(server.id)).set("authorization", self.token).end(function (err, res) {
+					if (err) {
+						reject(new Error(err.response.text));
+					} else {
+						// remove channels of server then the server
+						for (var _iterator = server.channels, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : _iterator[Symbol.iterator]();;) {
+							var _ref;
+
+							if (_isArray) {
+								if (_i >= _iterator.length) break;
+								_ref = _iterator[_i++];
+							} else {
+								_i = _iterator.next();
+								if (_i.done) break;
+								_ref = _i.value;
+							}
+
+							var chan = _ref;
+
+							server.channels.remove(chan);
+						}
+						// remove server
+						self.servers.remove(server);
+						resolve();
+					}
+				});
+			} else {
+				reject(new Error("server did not resolve"));
+			}
+		});
+	};
+
 	// def login
 
 	InternalClient.prototype.login = function login(email, password) {