Merge last st2 features to master

Hi,

I merged the last `st2` features to `master` branch:

* Add `trim_trailing_white_space_before_diff` feature to master
* Prevent AttributeError in the console

As I said in my previous message, I tested all the diff features on both applications `st2` and `st3`.
Thus it seems that you can keep only one branch for now on.

Thank