fix #241 stop button lock (#362)

* fix #241 stop button lock

Adds a delay and animation to the stop and pause buttons

- short vibration when starting to push the buttons
- long vibration when action was executed
- Toast to show "Hold to stop/pause recording"

src/main/res/drawable/button_stop.xml

@@ -1,19 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?><!--
-Copyright 2013 Google Inc.
-
-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.
--->
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:drawable="@drawable/ic_button_stop_pressed" android:state_pressed="true" />
-    <item android:drawable="@drawable/ic_button_stop" />
-</selector>