Remove compose.set_mode in favor of compose.start

From Trac ticket #1503:

All of the calls to compose.set_mode() should be calling compose.start()
instead. Nearly all are impossible to trigger while already composing,
and by calling compose.set_mode() they just do the stuff in set_mode()
twice. The only case where this would change behavior, that I can see,
is if you press C, Shift-Tab to unfocus the compose box without
dismissing it and then press c (or vice versa). I think it's okay if we
clear the input fields in that unlikely case.

(imported from commit ba7f181ec9d1df90a443b0a754462a3a201dcabb)

zephyr/static/js/compose.js

@@ -422,22 +422,6 @@ exports.clear = function () {
     $("#send-status").hide(0);
 };
 
-// Set the mode of a compose already in progress.
-// Does not clear the input fields.
-exports.set_mode = function (mode) {
-    ui.change_tab_to('#home');
-    if (!is_composing_message) {
-        exports.start(mode);
-    }
-    if (mode === 'private') {
-        show('private');
-        is_composing_message = "private";
-    } else {
-        show('stream');
-        is_composing_message = "stream";
-    }
-};
-
 exports.composing = function () {
     return is_composing_message;
 };
@@ -638,7 +622,7 @@ $(function () {
             // when text gets added into the composebox.
             if (!compose.composing()) {
                 respond_to_sent_message = true;
-                compose.set_mode('stream');
+                compose.start('stream');
             }
             if (i === -1) {
                 // This is a paste, so there's no filename. Show the image directly
@@ -662,7 +646,7 @@ $(function () {
             var textbox = $("#new_message_content");
             if (!compose.composing()) {
                 respond_to_sent_message = true;
-                compose.set_mode('stream');
+                compose.start('stream');
             }
             textbox.val(textbox.val() + contents);
         }

zephyr/static/js/hotkey.js

@@ -246,11 +246,11 @@ function process_hotkey(e) {
         }
         return true;
     case 'compose': // 'c': compose
-        compose.set_mode('stream');
+        compose.start('stream');
         respond_to_sent_message = true;
         return true;
     case 'compose_private_message':
-        compose.set_mode('private');
+        compose.start('private');
         respond_to_sent_message = true;
         return true;
     case  'enter': // Enter: respond to message (unless we need to do something else)

zephyr/static/js/ui.js

@@ -1205,11 +1205,11 @@ $(function () {
     });
 
     $('.compose_stream_button').click(function (e) {
-        compose.set_mode('stream');
+        compose.start('stream');
         return false;
     });
     $('.compose_private_button').click(function (e) {
-        compose.set_mode('private');
+        compose.start('private');
         return false;
     });