Added reply all/forward hint

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -872,7 +872,20 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
         fabReply.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
+                boolean reply_hint = prefs.getBoolean("reply_hint", false);
+                if (reply_hint)
                     onReply("reply");
+                else
+                    new AlertDialog.Builder(getContext())
+                            .setMessage(R.string.title_reply_hint)
+                            .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                                @Override
+                                public void onClick(DialogInterface dialog, int which) {
+                                    prefs.edit().putBoolean("reply_hint", true).apply();
+                                    onReply("reply");
+                                }
+                            })
+                            .show();
             }
         });
 

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -78,7 +78,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
 
     private final static String[] RESET_QUESTIONS = new String[]{
             "welcome", "crash_reports_asked", "review_asked", "review_later", "why",
-            "html_always_images", "print_html_confirmed",
+            "reply_hint", "html_always_images", "print_html_confirmed",
             "identities_asked", "cc_bcc", "inline_image_hint", "compose_reference", "send_dialog",
             "setup_advanced"
     };

app/src/main/res/values/strings.xml

@@ -688,6 +688,7 @@
     <string name="title_ask_help">Help improve FairEmail</string>
     <string name="title_ask_reporting">Send error reports?</string>
     <string name="title_reporting_why">Error reporting will help improve FairEmail</string>
+    <string name="title_reply_hint">You can reply to all, forward, etc via the double arrow action menu just below the message header</string>
 
     <string name="title_ask_review">Please review FairEmail</string>
     <string name="title_ask_review_rationale">