Add information about rich text format dependencies.
Use gitlab_git 5.4.0 without BROKEN_DIFF constant

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve compare logic for EmailOnPush service

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix link for MR diff download

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

Markup Dependencies
 Merge branch 'refactor_compare' into 'master'

Refactor Compare logic

Updated gitlab_git to version 5.4.0.
Fixes MR diff download link in case of huge diff.
Fixes #1026