Port Signal's emoji implementation to Briar

Add functionality to save and restore recently used Emojis

Update emoji and add new categories based on AOSP's XML file

briar-android/src/org/briarproject/android/view/TrustIndicatorView.java

@@ -0,0 +1,55 @@
+package org.briarproject.android.view;
+
+import android.content.Context;
+import android.support.annotation.UiThread;
+import android.support.v4.content.ContextCompat;
+import android.util.AttributeSet;
+import android.widget.ImageView;
+
+import org.briarproject.R;
+import org.briarproject.api.identity.Author.Status;
+
+import static org.briarproject.api.identity.Author.Status.OURSELVES;
+
+@UiThread
+public class TrustIndicatorView extends ImageView {
+
+	public TrustIndicatorView(Context context) {
+		super(context);
+	}
+
+	public TrustIndicatorView(Context context, AttributeSet attrs) {
+		super(context, attrs);
+	}
+
+	public TrustIndicatorView(Context context, AttributeSet attrs,
+			int defStyleAttr) {
+		super(context, attrs, defStyleAttr);
+	}
+
+	public void setTrustLevel(Status status) {
+		int res;
+		switch (status) {
+			case ANONYMOUS:
+				res = R.drawable.trust_indicator_anonymous;
+				break;
+			case UNVERIFIED:
+				res = R.drawable.trust_indicator_unverified;
+				break;
+			case VERIFIED:
+				res = R.drawable.trust_indicator_verified;
+				break;
+			case OURSELVES:
+				res = R.drawable.ic_our_identity_black;
+				break;
+			default:
+				res = R.drawable.trust_indicator_unknown;
+		}
+		setImageDrawable(ContextCompat.getDrawable(getContext(), res));
+		setVisibility(VISIBLE);
+
+		invalidate();
+		requestLayout();
+	}
+
+}