Rename PostCSS files to .pcss (#9013)

* Rename PostCSS files to `.pcss`

* Make Stylelint happy

* Delint

* Rename new files too

* delint

* Fix bad comment placement

res/css/views/dialogs/_SetEmailDialog.pcss

@@ -0,0 +1,33 @@
+/*
+Copyright 2017 Vector Creations Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_SetEmailDialog_email_input {
+    border-radius: 3px;
+    border: 1px solid $input-border-color;
+    padding: 9px;
+    color: $input-fg-color;
+    background-color: $background;
+    font-size: $font-15px;
+    width: 100%;
+    max-width: 280px;
+    margin-bottom: 10px;
+}
+
+.mx_SetEmailDialog_email_input:focus {
+    outline: none;
+    box-shadow: none;
+    border: 1px solid $accent;
+}