RingMainWindow : replace text tabs by icons

[aviau: add LICENSE file]

Reviewed-By: Alexandre Viau <alexandre@alexandreviau.net>
Change-Id: I60c9fd344e7597cb4bc337a8c1e740efa8287260
diff --git a/pixmaps/LICENSE b/pixmaps/LICENSE
new file mode 100644
index 0000000..52ebc55
--- /dev/null
+++ b/pixmaps/LICENSE
@@ -0,0 +1,21 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+
+Files: ic_history_black_24px.svg
+       ic_people_black_24px.svg
+       ic_question_answer_black_24px.svg
+       ic_verified_user_black_24px.svg
+Copyright: 2014-2017 Material Design Authors
+License: Apache-2.0
+
+License: Apache-2.0
+ 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.