Fix don't input Space with Shift using Japanese IME on Yosemite

https://gist.github.com/yamaya/dc21bb9a2c299c31bab8

Author: splhack

src/MacVim/MMTextViewHelper.m

@@ -187,6 +187,11 @@ - (void)keyDown:(NSEvent *)event
         // with Ctrl-6 or Ctrl-^ when IM is active.
         [self doKeyDown:@"\x1e"];
         string = nil;
+#if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_10)
+    } else if ((flags & NSShiftKeyMask) && [string isEqualToString:@" "]) {
+        // HACK! for Yosemite - Fix for Shift+Space inputing
+        // do nothing
+#endif
     } else {
         // HACK!  interpretKeyEvents: may call insertText: or
         // doCommandBySelector:, or it may swallow the key (most likely the