patch 8.2.1961: various comments can be improved

Problem:    Various comments can be improved.
Solution:   Various comment adjustments.

src/dict.c

@@ -22,6 +22,7 @@ static dict_T		*first_dict = NULL;
 
 /*
  * Allocate an empty header for a dictionary.
+ * Caller should take care of the reference count.
  */
     dict_T *
 dict_alloc(void)

src/gui_motif.c

@@ -1242,7 +1242,6 @@ add_pixmap_args(vimmenu_T *menu, Arg *args, int n)
     }
     else
     {
-	// Test_colorscheme()
 	if (menu->xpm_fname != NULL)
 	{
 	    XtSetArg(args[n], XmNpixmapFile, menu->xpm_fname); n++;

src/structs.h

@@ -1688,7 +1688,8 @@ struct funccall_S
 #ifdef FEAT_PROFILE
     proftime_T	prof_child;	// time spent in a child
 #endif
-    funccall_T	*caller;	// calling function or NULL
+    funccall_T	*caller;	// calling function or NULL; or next funccal in
+				// list pointed to by previous_funccal.
 
     // for closure
     int		fc_refcount;	// number of user functions that reference this

src/testdir/shared.vim

@@ -223,7 +223,7 @@ func s:feedkeys(timer)
   call feedkeys('x', 'nt')
 endfunc
 
-" Get $VIMPROG to run Vim executable.
+" Get $VIMPROG to run the Vim executable.
 " The Makefile writes it as the first line in the "vimcmd" file.
 func GetVimProg()
   if !filereadable('vimcmd')

src/testdir/test_netbeans.vim

@@ -845,6 +845,7 @@ func Nb_quit_with_conn(port)
   call writefile([], "Xnetbeans")
   let after =<< trim END
     source shared.vim
+    set cpo&vim
 
     func ReadXnetbeans()
       let l = readfile("Xnetbeans")

src/time.c

@@ -497,10 +497,12 @@ check_due_timer(void)
 	    may_garbage_collect = FALSE;
 	    save_vimvars(&vvsave);
 
+	    // Invoke the callback.
 	    timer->tr_firing = TRUE;
 	    timer_callback(timer);
 	    timer->tr_firing = FALSE;
 
+	    // Restore stuff.
 	    timer_next = timer->tr_next;
 	    did_one = TRUE;
 	    timer_busy = save_timer_busy;

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1961,
 /**/
     1960,
 /**/