Update gitlab-grit to newer version with normal diff collection. Show if file mode was changed

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'file-mode-changed' into 'master'

Show file mode changes on commit page

## Before:

![Screenshot 2014-06-14 22.55.18](https://dev.gitlab.org/uploads/dzaporozhets/gitlabhq/3f89dfa841/Screenshot_2014-06-14_22.55.18.png)

## After:

![Screenshot 2014-06-14 22.54.11](https://dev.gitlab.org/uploads/dzaporozhets/gitlabhq/5e7550d595/Screenshot_2014-06-14_22.54.11.png)