Simple Empty State Messages

This implements very basic and simple empty state messages for the
current features.

Closes #327

briar-android/res/layout/briar_recycler_view.xml

@@ -24,8 +24,10 @@
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
 		android:layout_centerInParent="true"
+		android:gravity="center"
 		android:padding="@dimen/margin_activity_horizontal"
+		android:text="@string/no_data"
 		android:textSize="@dimen/text_size_large"
-		android:text="@string/no_data"/>
+		tools:text="@string/no_contacts"/>
 
 </RelativeLayout>
\ No newline at end of file

briar-android/res/values/strings.xml

@@ -39,7 +39,7 @@
 	<string name="settings_button">Settings</string>
 	<string name="sign_out_button">Sign Out</string>
 	<string name="contact_list_title">Contacts</string>
-	<string name="no_contacts">No contacts</string>
+	<string name="no_contacts">It seems that you are new here and have no contacts yet.\n\nTap the + icon at the top and follow the instructions to add some friends to your list.\n\nPlease remember: You can only add new contacts face-to-face to prevent anyone from impersonating you or reading your messages in the future.</string>
 	<string name="add_contact_title">Add a Contact</string>
 	<string name="add_contact_title_step">Add a Contact - Step %1$d/%2$d</string>
 	<string name="your_nickname">Choose the identity you want to use:</string>
@@ -68,10 +68,12 @@
 	<string name="authenticating_with_device">Authenticating with device\u2026</string>
 	<string name="connection_aborted_local">Connection aborted by us! This could mean that someone is trying to interfere with your connection</string>
 	<string name="connection_aborted_remote">Connection aborted by your contact! This could mean that someone is trying to interfere with your connection</string>
-	<string name="no_private_messages">No messages</string>
+	<string name="date_no_private_messages">No messages.</string>
+	<string name="no_private_messages">This is the conversation view.\n\nThere seems to be a lack of conversation.\n\nJust tap the input field at the bottom to start a conversation.</string>
 	<string name="private_message_hint">Type message</string>
 	<string name="message_sent_toast">Message sent</string>
-	<string name="no_forums">You don\'t have any forums.\n\nWhy don\'t you create a new one yourself or ask your contacts to share one with you?</string>
+	<string name="no_forums">You don\'t have any forums yet.\n\nWhy don\'t you create a new one yourself by tapping the + icon at the top?\n\nYou can also ask your contacts to share forums with you.</string>
+	<string name="no_forum_posts">This forum is empty.\n\nUse the pen icon at the top to compose the first post.\n\nFeeling lonely here? Share this forum with more of your contacts!</string>
 	<plurals name="forums_shared">
 		<item quantity="one">%d forum shared by contacts</item>
 		<item quantity="other">%d forums shared by contacts</item>
@@ -116,7 +118,6 @@
 	<string name="forum_shared_by">Shared by</string>
 	<string name="forum_shared_with">Shared with</string>
 	<string name="nobody">Nobody</string>
-	<string name="no_contacts_prompt">You don\'t have any contacts. Add a contact now?</string>
 	<string name="add_button">Add</string>
 	<string name="cancel_button">Cancel</string>
 	<string name="done_button">Done</string>

briar-android/src/org/briarproject/android/contact/ContactListAdapter.java

@@ -44,7 +44,7 @@ public class ContactListAdapter
 
 		// date of last message
 		if (item.isEmpty()) {
-			ui.date.setText(R.string.no_private_messages);
+			ui.date.setText(R.string.date_no_private_messages);
 		} else {
 			long timestamp = item.getTimestamp();
 			ui.date.setText(AndroidUtils.formatDate(ctx, timestamp));

briar-android/src/org/briarproject/android/forum/ForumActivity.java

@@ -110,6 +110,7 @@ public class ForumActivity extends BriarActivity implements
 				(BriarRecyclerView) findViewById(R.id.forum_discussion_list);
 		linearLayoutManager = new LinearLayoutManager(this);
 		recyclerView.setLayoutManager(linearLayoutManager);
+		recyclerView.setEmptyText(getString(R.string.no_forum_posts));
 		recyclerView.showProgressBar();
 
 		forumController