-[#1060] Added toggle to disable thumbnail loading.

-Added button to wipe metadata cache.
-Added more paddings on player buttons.
-Added new animations to main player secondary controls and play queue expand/collapse.
-Refactored play queue item touch callback for use in all players.
-Improved MediaSourceManager to better handle expired stream reloading.
-[#1186] Changed live sync button text to "LIVE".
-Removed MediaSourceManager loader coupling on main players.
-Moved service dependent expiry resolution to ServiceHelper.
-[#1186] Fixed livestream timeline updates causing negative time position.
-[#1186] Fixed livestream not starting from live-edge.
-Fixed main player system UI not retracting on playback start.

app/src/main/java/org/schabi/newpipe/settings/HistorySettingsFragment.java

@@ -1,12 +1,35 @@
 package org.schabi.newpipe.settings;
 
 import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v7.preference.Preference;
+import android.widget.Toast;
 
 import org.schabi.newpipe.R;
+import org.schabi.newpipe.util.InfoCache;
 
 public class HistorySettingsFragment extends BasePreferenceFragment {
+    private String cacheWipeKey;
+
+    @Override
+    public void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        cacheWipeKey = getString(R.string.metadata_cache_wipe_key);
+    }
+
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         addPreferencesFromResource(R.xml.history_settings);
     }
+
+    @Override
+    public boolean onPreferenceTreeClick(Preference preference) {
+        if (preference.getKey().equals(cacheWipeKey)) {
+            InfoCache.getInstance().clearCache();
+            Toast.makeText(preference.getContext(), R.string.metadata_cache_wipe_complete_notice,
+                    Toast.LENGTH_SHORT).show();
+        }
+
+        return super.onPreferenceTreeClick(preference);
+    }
 }