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/elements/_InlineSpinner.pcss

@@ -0,0 +1,28 @@
+/*
+Copyright 2017 New Vector 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_InlineSpinner {
+    display: inline;
+}
+
+.mx_InlineSpinner img, .mx_InlineSpinner_icon {
+    margin: 0px 6px;
+    vertical-align: -3px;
+}
+
+.mx_InlineSpinner_icon {
+    display: inline-block !important; // Override regular mx_Spinner_icon
+}