Removing oh-my-zsh
Creating a oh-my-zsh-custom directory

The oh-my-zsh configuration framework is very great but I want to Upload
my own customizations to GitHub. So I had done the following:

- Adding a oh-my-zsh submodule to hold it up-to-date but not must commit
  all the changes to my dotfiles-repo
- Creating a oh-my-zsh directory to store my own oh-my-zsh
  customizations
- Symlink the files of the oh-my-zsh-custom directory to the custom
  directory of oh-my-zsh