In my development team we started using Cloud9 IDE some time ago and discovered that it is inconvenient to use git mergtool with Cloud9.
In my offline setup I use meld as mergetool and that works great for me. The standard mergetool for Cloud9 is vimdiff which normally wouldn't pose a big problem. However the vimdiff command to switch windows (Ctrl-W) also closes my window.
I can think of a few workarounds like:
I have the feeling that there should be an easier solution or a different mergetool. Any ideas?
I had the same problem and I managed to use your first approach you mention. Follow the three tutorials starting here: http://vim.wikia.com/wiki/Mapping_keys_in_Vim_-Tutorial%28Part_1%29
That should help you to set it up as you wish. Good luck!