Redind keys to adhere to Emacs minor-mode conventions

As pointed out in issue #1, minor mode should not use `C-x g`. This pull request maps it to `C-c /` as the prefix for all minor mode shortcuts. I chose `/` because it reminds me of search engine [blekko](http://blekko.com/). 

```
C-c / t   google-this
C-c / w   google-word
C-c / s   google-symbol 
etc.
```