PLT-1800 Load server side locale from the config.json (#3202)

* PLT-1800 Load server side locale from the config.json

* Add support for locales with country specifics

* Fix localization on served locale file as plain/text

* Remove github.com/cloudfoundry/jibber_jabber as vendor dependency

* Fix get locale on login_controller

webapp/components/admin_console/multiselect_settings.jsx

@@ -0,0 +1,80 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+import React from 'react';
+import ReactSelect from 'react-select';
+
+import Setting from './setting.jsx';
+import FormError from 'components/form_error.jsx';
+
+export default class MultiSelectSetting extends React.Component {
+    constructor(props) {
+        super(props);
+
+        this.handleChange = this.handleChange.bind(this);
+        this.state = {error: false};
+    }
+
+    handleChange(newValue) {
+        const values = newValue.map((n) => {
+            return n.value;
+        });
+
+        if (!newValue || newValue.length === 0) {
+            this.setState({error: this.props.errorText});
+        } else if (this.props.mustBePresent && values.join(',').indexOf(this.props.mustBePresent) === -1) {
+            this.setState({error: this.props.notPresent});
+        } else {
+            this.props.onChange(this.props.id, values);
+            this.setState({error: false});
+        }
+    }
+
+    componentWillReceiveProps(newProps) {
+        if (newProps.mustBePresent && newProps.selected.join(',').indexOf(newProps.mustBePresent) === -1) {
+            this.setState({error: this.props.notPresent});
+        } else {
+            this.setState({error: false});
+        }
+    }
+
+    render() {
+        return (
+            <Setting
+                label={this.props.label}
+                inputId={this.props.id}
+                helpText={this.props.helpText}
+            >
+                <ReactSelect
+                    id={this.props.id}
+                    multi={true}
+                    labelKey='text'
+                    options={this.props.values}
+                    joinValues={true}
+                    disabled={this.props.disabled}
+                    noResultsText={this.props.noResultText}
+                    onChange={this.handleChange}
+                    value={this.props.selected}
+                />
+                <FormError error={this.state.error}/>
+            </Setting>
+        );
+    }
+}
+
+MultiSelectSetting.defaultProps = {
+    disabled: false
+};
+
+MultiSelectSetting.propTypes = {
+    id: React.PropTypes.string.isRequired,
+    values: React.PropTypes.array.isRequired,
+    label: React.PropTypes.node.isRequired,
+    selected: React.PropTypes.array.isRequired,
+    mustBePresent: React.PropTypes.string,
+    onChange: React.PropTypes.func.isRequired,
+    disabled: React.PropTypes.bool,
+    helpText: React.PropTypes.node,
+    noResultText: React.PropTypes.node,
+    errorText: React.PropTypes.node,
+    notPresent: React.PropTypes.node
+};