Improve vim-mode to catch input better if in 'start' mode

lib/ace/keyboardstate.js

@@ -165,10 +165,12 @@ KeyboardStateMapper.prototype = {
             if (binding.then) {
                 data.state = binding.then;
                 data.buffer = "";
+            }
+
+            // If no command is set, then execute the "null" fake command.
             if (result.command == null) {
                 result.command = "null";
             }
-            }
 
             return true;
         });

lib/ace/mode/vim.js

@@ -94,15 +94,22 @@ var vimStates = {
             ]
         },
         {
-            comment:    "Let all combos of Command, Ctrl, Optional pass...",
+            comment:    "Catch some keyboard input to stop it here",
             match: function(buffer, hashId, key, symbolicName) {
-                return hashId != 0 && !(hashId & 4);
+                // If no command keys are pressed, then catch the input.
+                if (hashId == 0) {
+                    return true;
+                }
+                // If only the shift key is pressed and a character key, then
+                // catch that input as well.
+                else if ((hashId == 4) && key.length == 1) {
+                    return true;
+                }
+                // Otherwise, we let the input got through.
+                else {
+                    return false;
+                }
             }
-        },
-        {
-            comment:    "...but stop all other input!",
-            key:    ".*",
-            exec:   "null"
         }
     ],
     insertMode: [